Display device

ABSTRACT

Provided is a touch detection function-equipped display device that can be manufactured while suppressing an increase of price. A display device is provided with a pixel array including a plurality of pixels arranged in a matrix form, and drive electrodes each of which is arranged to extend in a first direction in the pixel array. A drive signal is supplied to a first area in a first drive electrode among the drive electrodes, and a ground voltage is supplied to a second area extending in the first direction with respect to the first area to generate a magnetic field in the first drive electrode according to the drive signal at a time of detecting an external proximity object.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.15/448,062, filed Mar. 2, 2017, which application claims priority fromJapanese Patent Application No. 2016-046778 filed on Mar. 10, 2016, thecontent of which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a display device, and particularly to atouch detection function-equipped display device which is capable ofdetecting an external proximity object.

BACKGROUND OF THE INVENTION

Recently, a focus has been placed on a touch detection device, aso-called touch panel, which is capable of detecting an externalproximity object. The touch panel is provided as a touch detectionfunction-equipped display device in the state of being mounted on adisplay device, for example, a liquid crystal display device, or beingintegrated with the liquid crystal display device.

The external proximity object includes, for example, a touch panel whichallows a pen to be used. By allowing the pen to be used, for example, itis possible to designate a small area or input a handwritten letter.There are various types of techniques to detect touch by the pen. One ofthe various types of techniques is an electromagnetic induction system.This electromagnetic induction system can realize a high accuracy and ahigh writing pressure detection accuracy, also realize a hoveringdetection function in which the external proximity object is spacedapart from a touch panel surface, and so is an effective technique asthe technique of detecting the touch by the pen.

In addition, there is also a touch panel which allows a finger to beused as the external proximity object. It is unnecessary to prepare apen or the like when it is possible to use the finger, which allowssimplicity and convenience. For example, various button images and thelike are displayed on a touch detection function-equipped displaydevice, and the proximity of the finger to the button image is detectedby the touch panel. Accordingly, it is possible to use the touch panelinstead of a general mechanical button. Such a touch detectionfunction-equipped display device does not necessarily require aninformation input means such as a keyboard and a mouse, and so tends tobe widely used in portable information terminals or the like such as amobile phone as well as a computer.

There are also various types of technique to detect the touch by thefinger. For example, there are several systems such as an optical type,a resistance type, and a capacitance system. Among them, the capacitivesystem has a relatively simple structure, consumes low power, and so hasbeen used in a portable information terminal or the like.

The touch panel that allows the use of the finger is simple andconvenient, but it is not easy to designate a small area using thefinger, for example. Thus, desired is a touch panel which allows both apen and a finger to be used.

Touch detection techniques using the electromagnetic induction systemare described in, for example, Japanese Patent Application Laid-open No.10-49301 (Patent Document 1), Japanese Patent Application Laid-open No.2005-352572 (Patent Document 2), and Japanese Patent ApplicationLaid-open No. 2006-163745 (Patent Document 3).

SUMMARY OF THE INVENTION

A display device according to the present invention comprises: a pixelarray which includes a plurality of pixels arranged in a matrix form; aplurality of drive wirings each of which is arranged to extend in afirst direction in the pixel array; and a plurality of detection wiringswhich are arranged to extend in a second direction intersecting thefirst direction in the pixel array. Also, a periodically changingmagnetic field drive signal is supplied to a first area in a first drivewiring among the plurality of drive wirings, and a reference signal issupplied to a second area extending in the first direction with respectto the first area so as to generate a magnetic field around the firstdrive wiring according to the magnetic field drive signal at a time ofdetecting an external proximity object. Further, the magnetic fieldgenerated by the external proximity object depending on the magneticfield generated around the first drive wiring is detected by theplurality of detection wirings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating a relationship between anelectronic device including a touch detection function-equipped displaydevice and a pen;

FIG. 2A is an explanatory diagrams illustrating a principle of anelectromagnetic induction system;

FIG. 2B is an explanatory diagrams illustrating a principle of anelectromagnetic induction system;

FIG. 3A is a waveform diagram illustrating a principle of theelectromagnetic induction system;

FIG. 3B is a waveform diagram illustrating a principle of theelectromagnetic induction system;

FIG. 4A is a plan view schematically illustrating a configuration of adisplay device according to an embodiment;

FIG. 4B is a cross-sectional view schematically illustrating aconfiguration of a display device according to an embodiment;

FIG. 5A is an explanatory diagram illustrating a principle of acapacitance system;

FIG. 5B is an explanatory diagram illustrating a principle of acapacitance system;

FIG. 5C is an explanatory diagram illustrating a principle of acapacitance system;

FIG. 6A is a cross-sectional view illustrating a schematic cross sectionof the display device;

FIG. 6B is a cross-sectional view illustrating a schematic cross sectionof the display device;

FIG. 7 is a plan view illustrating a magnetic field generation coil anda magnetic field detection coil;

FIG. 8 is a block diagram illustrating a configuration of a displaydevice according to a first embodiment;

FIG. 9 is a plan view illustrating a configuration of a module of thedisplay device according to the first embodiment;

FIG. 10 is a plan view illustrating a configuration of a display panelof the display device according to the first embodiment;

FIG. 11 is a cross-sectional view illustrating a configuration of thedisplay device according to the first embodiment;

FIG. 12 is a circuit diagram illustrating a circuit configuration of thedisplay panel of the display device according to the first embodiment;

FIG. 13A is an explanatory diagram illustrating a touch detectionoperation of the display device according to the first embodiment;

FIG. 13B is an explanatory diagram illustrating a touch detectionoperation of the display device according to the first embodiment;

FIG. 14 is a block diagram illustrating a configuration of a selectiondrive circuit of the display device according to the first embodiment;

FIG. 15A is a waveform diagram illustrating a waveform in a magneticfield generation period of the display device according to the firstembodiment;

FIG. 15B is a waveform diagram illustrating a waveform in a magneticfield generation period of the display device according to the firstembodiment;

FIG. 15C is a waveform diagram illustrating a waveform in a magneticfield generation period of the display device according to the firstembodiment;

FIG. 16 is a schematic plan view illustrating a magnetic field touchdetection operation of the display device according to the firstembodiment;

FIG. 17 is a schematic plan view illustrating the magnetic field touchdetection operation of the display device according to the firstembodiment;

FIG. 18 is a schematic plan view illustrating an electric field touchdetection operation of the display device according to the firstembodiment;

FIG. 19 is a plan view schematically illustrating a configuration of thedisplay device according to the first embodiment;

FIG. 20 is a perspective view schematically illustrating a configurationof the display device according to the first embodiment;

FIG. 21 is a perspective view schematically illustrating a configurationof a display device according to a modified example of the firstembodiment;

FIG. 22 is a plan view illustrating a configuration of a display deviceaccording to a second embodiment;

FIG. 23 is a plan view illustrating an operation of the display deviceaccording to the second embodiment;

FIG. 24 is a plan view illustrating the operation of the display deviceaccording to the second embodiment;

FIG. 25A is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25B is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25C is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25D is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25E is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25F is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25G is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25H is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 25I is a timing diagram illustrating an operation of a displaydevice according to a third embodiment;

FIG. 26A is a timing diagram illustrating the operation of the displaydevice according to the third embodiment;

FIG. 26B is a timing diagram illustrating the operation of the displaydevice according to the third embodiment;

FIG. 26C is a timing diagram illustrating the operation of the displaydevice according to the third embodiment;

FIG. 26D is a timing diagram illustrating the operation of the displaydevice according to the third embodiment;

FIG. 26E is a timing diagram illustrating the operation of the displaydevice according to the third embodiment;

FIG. 26F is a timing diagram illustrating the operation of the displaydevice according to the third embodiment;

FIG. 27 is a circuit diagram illustrating a configuration of a detectioncircuit of the display device according to the third embodiment;

FIG. 28 is a plan view illustrating a configuration of a display deviceaccording to a fourth embodiment.

FIG. 29 is a circuit diagram illustrating a principle of touch detectionof the display device according to the fourth embodiment;

FIG. 30 is a plan view illustrating a configuration of a display deviceaccording to a modified example of the fourth embodiment;

FIG. 31 is a plan view schematically illustrating a configuration of adisplay device according to a fifth embodiment;

FIG. 32 is a circuit diagram illustrating a configuration of a selectiondrive circuit of the display device according to the fifth embodiment;

FIG. 33 is a circuit diagram illustrating a configuration of a selectiondrive circuit of a display device according to a modified example of thefifth embodiment;

FIG. 34 is a schematic plan view illustrating a configuration of adisplay device according to a sixth embodiment;

FIG. 35 is a circuit diagram illustrating a configuration of a selectiveconnection circuit of the display device according to the sixthembodiment;

FIG. 36 is a block diagram illustrating a configuration of a displaydevice that has been studied by the present inventors;

FIG. 37 is a block diagram illustrating a configuration of the displaydevice that has been studied by the present inventors;

FIG. 38 is a plan view illustrating a configuration of a display deviceaccording to a modified example of the fourth embodiment;

FIG. 39 is a plan view illustrating a configuration of a display deviceaccording to a modified example of the fourth embodiment; and

FIG. 40 is a plan view illustrating a configuration of a display deviceaccording to a modified example of the fourth embodiment.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

Hereinafter, each embodiment of the present invention will be describedwith reference to the drawings. Incidentally, the disclosure is mere anexample, and a matter that those skilled in the art easily think upabout appropriate alternations while keeping a gist of the invention isoff course included with the present invention. In addition, there arecases in which a width, a thickness, a shape and the like of eachportion of the drawings are schematically illustrated as compared toactual aspects in order for more clear description, but the drawings aremere examples, and do not limit the interpretation of the presentinvention.

In addition, the same reference numerals are applied to the sameelements that have been described in relation to the foregoing drawingsin the present specification and the respective drawings, and detaileddescriptions thereof will be appropriately omitted in some cases.

The following description is given by exemplifying a touch detectionfunction-equipped liquid crystal display device as a touch detectionfunction-equipped display device. However, the invention is not limitedthereto, and can be applied also to a touch detection function-equippedOLED display device. In addition, although the description has beengiven by exemplifying two types of an electromagnetic induction system,a case of employing the latter system will be described hereinafter. Inthe latter system, a battery is not necessarily mounted in a pen, and soit is possible to reduce a size of the pen and/or to improve a degree offreedom in shape.

The electromagnetic induction system includes a system in which: a coiland a battery are mounted to a pen; a magnetic field is generated by thepen; and magnetic field energy is detected by a touch panel. In thiscase, the touch panel needs to include a sensor plate that receives themagnetic field energy. Further, there is another system in which: a coiland a capacitor are mounted in a pen; a magnetic field is generated by atouch panel; magnetic field energy is stored in the capacitor mounted inthe pen; and then is detected by the touch panel. In the case of thissystem, the magnetic field is generated by the touch panel, and a sensorplate to receive the magnetic field energy from the pen is required.

It is necessary to add the sensor plate receiving electromagnetic energyin order to realize the touch detection function-equipped display devicein any of the electromagnetic induction systems, which leads to anincrease of price (production cost).

In addition, required is a sensor plate for detection of a change incapacitance even in the capacitance system that detects the touch by thefinger. Thus, it is necessary to add the sensor plate in order torealize the touch detection function-equipped display device, whichleads to an increase of price.

In order to enable detection of both the touch by the pen and the touchby the finger, it is necessary to add the respective sensor plates,which lead to a further increase of price. For example, it isconceivable to suppress the increase of price by utilizing a part of thesensor plate used in the electromagnetic induction system also as a partof the sensor plate used in the capacitance system. However, it isrequired to perform control for switching the commonly utilized part inthe case of the common utilization, and such control is complicated. Inaddition, a control circuit for the control is increased, whichrestricts the suppression of the increase of price.

An object of the present invention is to provide a touch detectionfunction-equipped display device that can be manufactured whilesuppressing an increase of price.

A display device according to an aspect of the present inventionincludes: a pixel array which includes a plurality of pixels arranged ina matrix form; a plurality of drive wirings each of which is arranged toextend in a first direction in the pixel array; and a plurality ofdetection wirings which are arranged to extend in a second directionintersecting the first direction in the pixel array. Here, aperiodically changing magnetic field drive signal is supplied to a firstarea in a first drive wiring among the plurality of drive wirings, and areference signal is supplied to a second area extending in the firstdirection with respect to the first area at a time of detecting anexternal proximity object. Accordingly, a magnetic field is generatedaround the first drive wiring depending on the magnetic field drivesignal. A magnetic field generated by the external proximity object ischanged depending on whether the external proximity object is proximateto the first drive wiring. This magnetic field generated by the externalproximity object is detected by the plurality of detection wirings.

For example, a configuration where two drive wirings each extending inthe first direction are electrically connected to form a coil isconsidered in order to generate the magnetic field. In this case,connecting control is required between the two drive wirings. In regardto this, the connecting control is not required between the drivewirings, and the control becomes easy in the display device according toan aspect. In addition, it is possible to suppress an increase of acontrol circuit(s). As a result, it is possible to suppress an increaseof price of the touch detection function-equipped display device.

Also, in the display device according to an aspect of the presentinvention, the above-described plurality of drive wirings include asecond drive wiring, the second drive wiring being arranged to beproximate to the first drive wiring and having a first area proximate tothe first area, and a second area proximate to the second area. Here,the reference signal is supplied to the first area of the second drivewiring, and the magnetic field drive signal is supplied to the secondarea of the second drive wiring at the time of detecting the externalproximity object. In this case, the magnetic field generated around thefirst drive wiring and a magnetic field generated around the seconddrive wiring are superimposed on each other in an area between the firstand second drive wirings. Accordingly, it is possible to strengthen themagnetic field thus generated.

Further, a display device according to an aspect of the presentinvention is a display device that, in a display area with first andsecond sides opposing each other, has a plurality of drive wiringsarranged between the first and second sides and parallel to each other.The display device includes a first drive circuit connected to one endportion of each of the plurality of drive wirings, and a second drivecircuit connected to the other end portion of each of the plurality ofdrive wirings. Here, the first drive circuit supplies a magnetic fielddrive signal to one end portion of a first drive wiring arranged to beproximate to the first side, and the second drive circuit supplies areference signal to the other end portion of the first drive wiring. Atthis time, the first drive circuit supplies the reference signal to oneend portion of a second drive wiring which is arranged to be closer tothe second side than the first drive wiring and to sandwich a thirddrive wiring with the first drive wiring, and the second drive circuitsupplies the magnetic field drive signal to the other end portion of thesecond drive wiring.

A strong magnetic field is generated between the first and second drivewirings, and is applied to the external proximity object by supplyingthe magnetic field drive signal and the reference signal to the firstand second drive wirings.

The first and second drive circuits detect the external proximity objectproximate to the display area during a display period for one frame inthe display area by supplying the magnetic field drive signal and thereference signal to the drive wirings selected among the plurality ofdrive wirings so that drive wirings respectively corresponding to thefirst and second drive wirings are moved from the first side to thesecond side.

Accordingly, it is possible to detect the external proximity objectproximate to the display area while preventing the control from beingcomplicated.

First Embodiment

A touch detection function-equipped liquid crystal display device(hereinafter, simply referred to also as a display device) according toa first embodiment has both functions of touch detection by anelectromagnetic induction system and touch detection by a capacitancesystem. That is, it is possible to perform the detection of touch by thepen and the detection of touch by the finger. First, each principle ofthe electromagnetic induction system and the capacitance system will bedescribed.

<Basic Principle of Electromagnetic Induction System>

FIG. 1 is an explanatory diagram schematically illustrating arelationship between an electronic device including the display deviceand the pen. In addition, FIGS. 2A to 3B are explanatory diagramsschematically illustrating the basic principle of the electromagneticinduction system.

In FIG. 1, the electronic device includes a display device 1 housed in ametal cover, a light guide plate, a sensor plate, and a magnetic sheet.The sensor plate is mounted between the display device 1 and the metalcover in the example illustrated in FIG. 1. Although a plurality ofcoils are provided in the sensor plate, FIG. 1 schematically illustratesone coil among the plurality of coils as a sensor plate-in coil(hereinafter, simply referred to also as a coil) L2.

Further, a coil and a capacitive element are built in a pen thatcorresponds to an external proximity object. FIG. 1 does not illustratethe capacitive element while schematically illustrating the coil builtin the pen as a pen-in coil (hereinafter, simply referred to also as acoil) L1. The coil L1 and the coil L2 are coupled by a magnetic field.

Incidentally, a TFT glass substrate, a color filter and a CF glasssubstrate, which are included in the display device 1, are drawn in FIG.1 in order to schematically illustrate a structure of the display device1. A plurality of layers are formed on the TFT glass substrate althoughnot illustrated. The color filter is formed on the CF glass substrate,and a liquid crystal layer not shown in Figure is sandwiched between thecolor filter and the TFT glass substrate. In addition, the light guideplate is fixed by a fixing part to be sandwiched between the displaydevice 1 and the sensor plate.

When the pen is proximate to (including contact) the electronic device,the coil L1 is proximate to the coil L2. Accordingly, the magnetic fieldcoupling between the coil L1 and the coil L2 is generated, and theproximity of the pen is detected.

Such detection will be described with reference to FIGS. 2A to 3B. FIG.2A illustrates a state in which the coil L2 generates a magnetic field,and FIG. 2B illustrates a state in which the coil L1 generates amagnetic field.

In FIGS. 2A and 2B, the coil L1 inside the pen and a pen-in capacitiveelement (hereinafter, also referred to simply as a capacitive element) Care connected in parallel, thereby forming a resonant circuit. A coil ofsingle-turn winding is illustrated as an example of the sensor plate-incoil L2, and has a pair of terminals. At a time of detecting touch bythe pen (during touch detection), one terminal PT of the coil L2 isconnected to output of a transmission amplifier AP1 for a predeterminedtime and, after elapse of the predetermined time, is connected to inputof a reception amplifier AP2 for a predetermined time. Further, theother terminal of the sensor plate-in coil L2 is connected to a groundvoltage Vss during the touch detection.

FIGS. 3A and 3B are waveform diagrams illustrating an operation duringthe touch detection. A horizontal axis represents time in FIGS. 3A and3B, FIG. 3A illustrates a waveform of output of the transmissionamplifier AP1, and FIG. 3B illustrates a waveform of output of thereception amplifier AP2.

When the one terminal PT of the coil L2 is connected to the output ofthe transmission amplifier AP1, a transmission signal IN whichperiodically changes is supplied to the input of the transmissionamplifier AP1. Accordingly, the transmission amplifier AP1 supplies aperiodically changing drive signal ϕ1 to the one terminal of the coil L2for a predetermined time (magnetic field generation period) TGTdepending on a change of the transmission signal IN as illustrated inFIG. 3A. Accordingly, the coil L2 generates a magnetic field. Magneticlines at this time are indicated by ϕG in FIG. 2A.

Since the magnetic lines ϕG are generated around a winding of the coilL2, the magnetic field at an inner side of the coil L2 becomes strong.When the coil L1 is proximate to the coil L2 and, for example, a centralaxis LO of the coil L1 is present at the inner side of the coil L2 asillustrated in FIG. 2A, the magnetic lines of the coil L2 reach the coilL1. That is, the coil L1 is arranged inside the magnetic field generatedby the coil L2, and the coil L1 and the coil L2 are magneticallycoupled. The coil L2 generates the magnetic field, which periodicallychanges, depending on the change of the drive signal ϕ1. Thus, aninduced voltage is generated in the coil L1 according to action ofmutual induction between the coil L2 and the coil L1. The capacitiveelement C is charged by the induced voltage generated by the coil L1.

After the predetermined time, the one terminal PT of the coil L2 isconnected to input of the reception amplifier AP2 for a predeterminedtime (a magnetic field detection period or a current detection period)TDT. If the capacitive element C is charged in the previous magneticfield generation period TGT, the coil L1 generates a magnetic fieldusing electric charges charged in the capacitive element C in themagnetic field detection period TDT. Magnetic lines of the coil L1generated by the electric charges charged in the capacitive element Care indicated by ϕD in FIG. 2B.

If the pen-in coil L1 is proximate to the sensor plate-in coil L2 duringthe touch detection, that is, during the magnetic field generationperiod TGT and the magnetic field detection period TDT, the charging ofthe capacitive element C is performed in the magnetic field generationperiod TGT, and the magnetic lines ϕD of the coil L1 reach the coil L2in the magnetic field detection period TDT. Since the resonant circuitis configured by the coil L1 and the capacitive element C, the magneticfield generated by the coil L1 is changed depending on a time constantof the resonant circuit. As the magnetic field generated by the coil L1is changed, an induced voltage is generated in the coil L2. A signal ischanged in the one terminal PT of the coil L2 due to the inducedvoltage. This change of the signal is inputted to the receptionamplifier AP2 as a detection signal ϕ2, is amplified, and outputted fromthe reception amplifier AP2 as a sensor signal OUT in the magnetic fielddetection period TDT.

Meanwhile, if the pen-in coil L1 is not proximate to the sensor plate-incoil L2 during the touch detection, the capacitive element C is notcharged or a charge amount to be charged decreases in the magnetic fieldgeneration period TGT. As a result, the magnetic lines ϕD of themagnetic field generated by the coil L1 do not reach the coil L2 in themagnetic field detection period TDT. Thus, the detection signal φ2 inthe one terminal PT of the coil L2 is not changed in the magnetic fielddetection period TDT.

FIGS. 3A and 3B illustrate both states when the pen-in coil L1 isproximate to and is not proximate to the sensor plate-in coil L2. Thatis, a state when the coil L1 is not proximate to the coil L2 isillustrated in a left side in FIGS. 3A and 3B, and a state when the coilL1 is proximate to the coil L2 is illustrated in a right side. Thus, thedetection signal ϕ2 is not changed in the magnetic field detectionperiod TDT illustrated in the left side in FIG. 3B, and the detectionsignal ϕ2 is changed in the magnetic field detection period TDTillustrated in the right side. It is possible to detect the touch by thepen by determining pen presence in a case where the detection signal ϕ2is changed, and pen absence in a case where the detection signal ϕ2 isnot changed.

FIGS. 3A and 3B illustrate the determination on the pen presence and thepen absence, and it is also possible to determine a distance between thepen and the sensor plate or determine writing pressure of the pen sincea value of the detection signal ϕ2 is changed depending on a distancebetween the coil L1 and the coil L2.

<Basic Principle of Capacitive System>

Next, the basic principle of the capacitive system will be described.Here, a description will be given by exemplifying a case of detectingtouch by the finger using a signal wiring formed in the display device 1illustrated in FIG. 1. That is, the description will be given regardinga case where the sensor plate of the capacitance system is integratedwith the display device. First, the configuration of the display device1 illustrated in FIG. 1 will be described in more detail. FIGS. 4A and4B are diagrams schematically illustrating the configuration of thedisplay device 1. Here, FIG. 4A is a plan view schematicallyillustrating a plane of the display device 1, and FIG. 4B is across-sectional view schematically illustrating a cross section of thedisplay device 1.

In FIG. 4A, TL(0) to TL(p) represent drive electrodes which areconfigured using layers formed on a first main surface TSF1 of a TFTglass substrate TGB (first substrate). In addition, RL(0) to RL(p)represent detection electrodes which are configured using layers formedon a first main surface CSF1 of a CF glass substrate CGB (secondsubstrate). The TFT glass substrate TGB is provided with the first mainsurface TSF1 and a second main surface TSF2 (FIG. 4B) which opposes thefirst main surface TSF1. Although a plurality of layers are formed onthe first main surface TSF1 of the TFT glass substrate TGB, FIGS. 4A and4B illustrate only the layers forming the drive electrodes TL(0) toTL(p).

Similarly, the CF glass substrate CGB is provided with the first mainsurface CSF1 and a second main surface CSF2 (FIG. 4B) which opposes thefirst main surface CSF1. FIGS. 4A and 4B illustrate only the layersforming the detection electrodes RL(0) to RL(p) arranged on the firstmain surface CSF1. FIG. 4A illustrates the TFT glass substrate TGB andthe CF glass substrate CGB which are isolated from each other tofacilitate the understanding. Specifically, the first main surface TSF1of the TFT glass substrate TGB (first substrate) and the second mainsurface CSF2 of the CF glass substrate CGB (second substrate) arearranged to oppose each other with the liquid crystal layer sandwichedtherebetween as illustrated in FIG. 4B.

Although the plurality of layers, the liquid crystal layer, and the likeare sandwiched between the first main surface TSF1 of the TFT glasssubstrate TGB and the second main surface CSF2 of the CF glass substrateCGB, FIGS. 4A and 4B illustrate only the drive electrodes TL(0) toTL(n+2), the liquid crystal layer and the color filter which aresandwiched between the first main surface TSF1 and the second mainsurface CSF2. In addition, the plurality of detection electrodes RL(0)to RL(p) and a polarizing plate are arranged on the first main surfaceCSF1 of the CF glass substrate CGB as illustrated in FIG. 4A. FIG. 4Billustrates only a detection electrode RL(n) among the plurality ofdetection electrodes RL(0) to RL(p) as an example of the detectionelectrode.

In the present specification, the description is given a state when thedisplay device 1 is viewed as a plain view from the first main surfacesCSF1 and TSF1 of the CF glass substrate CGB and the TFT glass substrateTGB side as illustrated in FIG. 4B. That is, the plan view is the statethat is viewed from sides of the first main surfaces CSF1 and TSF1 ofthe CF glass substrate CGB and the TFT glass substrate TGB. Thus, it hasbeen described that the detection electrode and the polarizing plate arearranged on the first main surface CSF1 of the CF glass substrate CGBside. But, the detection electrode and the polarizing plate are arrangedon right, left or lower side of the CF glass substrate CGB, for example,when a direction of the viewing is changed. In FIG. 4B, numeral 13represents an amplifier circuit which is connected to the detectionelectrode RL(n).

When seen in the plan view from the first main surface CSF1 and TSF1sides, the drive electrodes TL(0) to TL(p) extend in a row direction(horizontal direction) and are arranged in parallel in a columndirection (vertical direction) on the first main surface TSF1 of the TFTglass substrate TGB as illustrated in FIG. 4A. In addition, thedetection electrodes RL(0) to RL(p) extend in the column direction(vertical direction) and are arranged in parallel the row direction(horizontal direction) on the first main surface CSF1 of the CF glasssubstrate CGB as illustrated in FIG. 4A.

As illustrated in FIG. 4B, the CF glass substrate CGB, the liquidcrystal layer, and the like are sandwiched between the drive electrodesTL(0) to TL(p) and the detection electrodes RL(0) to RL(p). Thus, thedrive electrodes TL(0) to TL(p) and the detection electrodes RL(0) toRL(p) cross each other when seen in the plan view, but are electricallyisolated from each other. Since capacitance is present between the driveelectrode and the detection electrode, this capacitance is illustratedin broken lines as a capacitive element in FIG. 4B. Incidentally, thedrive electrodes TL(0) to TL(p) are isolated from each other, and thedetection electrodes RL(0) to RL(p) are also isolated from each other.

A drive signal for display (display drive signal) is supplied to thedrive electrodes TL(0) to TL(p) at a time of display, and a drive signalfor touch detection is supplied thereto at a time of detecting the touchby the finger.

In the first embodiment, the detection of touch by the finger isperformed using the electric field, and the detection of touch by thepen is performed using the magnetic field (see FIG. 1, FIGS. 2A and 2B,and FIGS. 3A and 3B). Thus, the detection of touch using the magneticfield will be referred to as magnetic field touch detection, and thedetection of touch using the electric field will be referred to aselectric field touch detection in the present specification. Althoughwill be described later, the drive signal for touch detection issupplied to the drive electrodes TL(0) to TL(p) even at the time ofmagnetic field touch detection. Thus, a drive signal which correspondsto each of the display, the electric field touch detection, and themagnetic field touch detection is supplied to the drive electrodes TL(0)to TL(p) at each time of the display, the electric field touchdetection, and the magnetic field touch detection. That is, the driveelectrodes TL(0) to TL(p) are commonly used (shared) among the time ofdisplay, the time of electric field touch detection, and the time ofmagnetic field touch detection. Each of the drive electrodes TL(0) toTL(p) can be regarded as a common electrode when seen from the viewpointof being commonly used.

A drive signal Tx for an electric field is supplied to the driveelectrodes TL(0) to TL(p) in a period for the electric field touchdetection. A signal whose voltage periodically changes is supplied asthe drive signal Tx to the drive electrode selected so as to detect thetouch, and a predetermined fixed voltage, for example, is supplied asthe drive signal Tx to the drive electrode which is not selected so asnot to detect the touch. The drive electrodes TL(0) to TL(p) aresequentially selected in this order, for example, in the electric fieldtouch detection period. Although FIG. 4A illustrates a state in whichthe signal with the periodically changing voltage is supplied to thedrive electrode TL(2) as a drive signal Tx(2), the drive electrodes aresequentially selected, for example, from the drive electrode TL(0) toTL(p), and the drive signal with the periodically changing voltage issupplied thereto.

On the other hand, the predetermined fixed voltage or a voltage inaccordance with image information to be displayed is supplied to thedrive electrodes TL(0) to TL(p) as the display drive signal in a periodfor the display.

Next, a basic principle of the capacitive system will be described withreference to FIGS. 5A to 5C. In FIGS. 5A to 5C, reference signs TL(0) toTL(p) indicate the drive electrodes illustrated in FIGS. 4A and 4B, andreference signs RL(0) to RL(p) indicate the detection electrodesillustrated in FIGS. 4A and 4B. In FIG. 5A, the respective driveelectrodes TL(0) to TL(p) extend in the row direction and are arrangedin parallel in the column direction. Further, the respective detectionelectrodes RL(0) to RL(p) extend in the column direction and arearranged in parallel in the row direction so as to cross the driveelectrodes TL(0) to TL(p). The liquid crystal layer and the like isarranged between the detection electrodes RL(0) to RL(p) and the driveelectrodes TL(0) to TL(p) so that a gap is formed between the detectionelectrodes RL(0) to RL(p) and the drive electrodes TL(0) to TL(p) asillustrated in FIG. 4B.

In FIG. 5A, each of numerals 12-0 to 12-p schematically illustrates aunit drive electrode driver. In FIG. 5A, the drive signals Tx(0) toTx(p) are outputted from the unit drive electrode driver 12-0 to 12-p.Further, each of numerals 13-0 to 13-p schematically illustrates a unitamplification circuit. In FIG. 5A, a pulse signal surrounded by ∘(circle) of a solid line indicates a waveform of the drive signal Tx tobe supplied to the selected drive electrode. The finger is representedby numeral FG as an external proximity object in FIG. 5A.

The pulse signal is supplied from the unit drive electrode driver 12-2to the drive electrode TL(2) as the drive signal Tx(2) in the example ofFIG. 5A. When the drive signal Tx(2), which is the pulse signal, issupplied to the drive electrode TL(2), an electric field is generatedbetween the drive electrode TL(2) and the crossing detection electrodeRL(n) as illustrated in FIG. 5B. At this time, when the finger FGtouches a position proximate to the drive electrode TL(2) of the liquidcrystal panel, an electric field is also generated between the finger FGand the drive electrode TL(2), and the electric field generated betweenthe drive electrode TL(2) and the detection electrode RL(n) is reduced.Accordingly, an electric charge amount between the drive electrode TL(2)and the detection electrode RL(n) is reduced. As a result, the electriccharge amount generated in response to the supply of the drive signalTx(2) is reduced by ΔQ at the time of the touch of the finger FG ascompared to the time of the non-touch thereof as illustrated in FIG. 5C.A difference in electric charge amount is represented as a difference involtage in the detection signal Rx(n), and is supplied to the unitamplification circuit 13-n and amplified.

Incidentally, a horizontal axis represents time, and a vertical axisrepresents the electric charge amount in FIG. 5C. The electric chargeamount increases (increases in an upper side in FIG. 5C) in response toa rise in voltage of the drive signal Tx(2), and the electric chargeamount increases (increases in a lower side in FIG. 5C) in response to adrop in voltage of the drive signal Tx(2). At this time, an increasingamount of electric charges is changed depending on absence or presenceof the touch of the finger FG Further, reset is performed before theelectric charge amount increases toward the lower side from afterincreasing toward the upper side, and reset is performed similarlybefore the electric charge amount increases toward the upper side fromafter increasing toward the lower side in FIG. 5C. In this manner, theelectric charge amount is vertically changed with the reset electriccharge amount as a reference. In other words, a signal change isgenerated in the detection electrode RL(n) in response to the touch.

When the drive electrodes TL(0) to TL(p) are sequentially selected andthe drive signals Tx(0) to Tx(p) which are the pulse signals aresupplied to the selected drive electrode, the detection signals Rx(0) toRx(p), each of which has a voltage value in response to whether thefinger FG touches the position proximate to each crossing portionbetween the selected drive electrode and the crossing plurality ofdetection electrodes RL(0) to RL(p), are outputted from each of theplurality of detection electrodes RL(0) to RL(p) crossing with theselected drive electrode. Each of the detection signals Rx(0) to Rx(p)is sampled, and is converted into a digital signal using ananalog/digital conversion unit at a time at which a gap ΔQ is generatedin the electric charge amount. A coordinate of the touched position canbe extracted by performing a signal processing of the converted digitalsignal.

<Integrated Structure of Display Device and Sensor Plate-in Coil>

The present inventors have considered that an electronic device becomescostly in a case of separately preparing the display device 1 and thesensor plate as illustrated in FIG. 1 because the sensor plate iscostly. Thus, the inventors have considered to form the coil L2 (FIG. 1)configuring the sensor plate using a layer of the display device 1, andto integrate the display device and the sensor plate.

FIGS. 6A and 6B are cross-sectional views illustrating schematic crosssections of the display device 1 with which the sensor plate isintegrated as a sensor layer (layer). FIGS. 6A and 6B are similar toFIG. 1, and thus, a different point will mainly be described. In FIG. 1,the sensor plate is prepared separately from the display device 1, andthe sensor plate is provided between the light guide plate and themagnetic sheet. On the contrary, the sensor layer is formed on the CFglass substrate CGB in FIG. 6A. In addition, the sensor layer is formedon the TFT glass substrate TGB in FIG. 6B. Accordingly, the sensor layercorresponding to the sensor plate is provided in the display device 1,and thus it is possible to suppress the increase of price.

As described in FIGS. 2A to 3B, the sensor plate-in coil L2 generatesthe magnetic field in the magnetic field generation period TGT, and themagnetic field generated by the pen-in coil L1 is detected by the sensorplate-in coil L2 in the magnetic field detection period TDT. That is,the sensor plate-in coil L2 is commonly used for generation of themagnetic field and detection of the magnetic field. In the case of beingcommonly used in this manner, the coil L2 is configured by the layerformed on the CF glass substrate CGB in FIG. 6A. Similarly, the coil L2is configured by the layer formed on the TFT glass substrate TGB in FIG.6B.

However, it is also possible to separately form the coil that generatesthe magnetic field in the magnetic field generation period TGT, and thecoil that detects the magnetic field in the magnetic field detectionperiod TDT. In this case, for example, the coil to generate the magneticfield (hereinafter, referred to also as a magnetic field generationcoil) can be formed using the sensor layer illustrated in FIG. 6B, andthe coil to detect the magnetic field (hereinafter, referred to also asa magnetic field detection coil) can be formed using the sensor layerillustrated in FIG. 6A. In addition, there are a plurality of layersthat can be used as the sensor layer on the TFT glass substrate TGB.Thus, it is also possible to separately form the magnetic fieldgeneration coil and the magnetic field detection coil using the sensorlayers illustrated in FIG. 6B.

FIG. 7 illustrates an example of the case of separately forming themagnetic field generation coil and the magnetic field detection coil.FIG. 7 illustrates the case where the magnetic field generation coil andthe magnetic field detection coil are configured using the layers formedon the TFT glass substrate TGB. In FIG. 7, for example, CX(n) to CX(n+2)represent the magnetic field generation coils and CY(n) to CY(n+2)represent the magnetic field detection coils. In FIG. 7, the driveelectrodes TL(0) to TL(p) described in FIGS. 4A and 4B are used as thelayers forming the magnetic field generation coils, and signal linesSL(0) to SL(p) to transmit image information are used as the layersforming the magnetic field detection coil. Although will be describedlater, the signal lines SL(0) to SL(p) are configured using the layersformed on the TFT glass substrate TGB, similarly to the drive electrodesTL(0) to TL(p), extend in the horizontal direction and are arranged inparallel in the vertical direction in FIG. 7.

As illustrated in FIGS. 4A, 4B and 7, the drive electrodes TL(0) toTL(p) extend in the horizontal direction to be parallel to each other.As illustrated in FIG. 7, one end portion of each of the driveelectrodes TL(n+1) and TL(n+2) and one end portion of each of the driveelectrodes TL(n+6) and TL(n+7) are electrically connected, and the otherend portion of each of the drive electrodes TL(n) to TL(n+2) and theother end portion of each of the drive electrodes TL(n+6) to TL(n+8) areelectrically connected in the magnetic field generation period TGT.Accordingly, a coil CX(n) with a three-turn winding is formed as awinding by using the drive electrodes TL(n) to TL(n+2) and TL(n+6) toTL(n+8). In the same manner, it is possible to form three-turn-windingcoils CX(n+1), CX(n+2) and so on by electrically connectingpredetermined drive electrodes in the magnetic field generation periodTGT.

Similarly, one end portion of each of the signal lines SL(n+1) andSL(n+2) and one end portion of each of the signal lines SL(n+6) andSL(n+7) are electrically connected, and the other end portion of each ofthe signal lines SL(n) to SL(n+2) and the other end portion of each ofthe signal lines SL(n+6) to SL(n+8) are electrically connected in themagnetic field detection period TDT. Accordingly, a coil CY(n) with athree-turn winding is formed as a winding by using the signal linesSL(n) to SL(n+2) and SL(n+6) to SL(n+8). In the same manner, it ispossible to form three-turn-winding coils CY(n+1), CY(n+2) and so on byelectrically connecting predetermined signal lines in the magnetic fielddetection period TDT.

The coils CX(n) to CX(n+2) and the coils CY(n) to CY(n+2) cross eachother in electrically isolated states. For example, one end portion ofthe drive electrode TL(n) forming the coil CX(n) corresponds to theterminal PT illustrated in FIGS. 2A and 2B, and the output from thetransmission amplifier AP1 illustrated in FIG. 1 is supplied thereto andthe ground voltage Vss is supplied to the other end portion of the driveelectrode TL(n+8) in the magnetic field generation period TGT.Accordingly, the magnetic field is generated in the coil CX(n) asdescribed in FIG. 2A. Electric charges are stored in the capacitiveelement C (FIGS. 2A and 2B) inside the pen by the magnetic fieldgenerated in the coil CX(n).

In the magnetic field detection period TDT, predetermined signal linesare electrically connected, and the coils CY(n) to CY(n+2) are formed.The coil L1 (FIG. 1) generates the magnetic field using the electriccharges stored in the capacitive element C inside the pen. The magneticfield generated at this time is detected by the coils CY(n) to CY(n+2).Accordingly, it is possible to detect the proximity of the pen or adistance between the pen and an area in close proximity thereto.

<Problem of Magnetic Field Generation Coil>

The present inventors have studied a configuration of a display devicein a case of using a magnetic field generation coil in anelectromagnetic induction system prior to the present invention. FIGS.36 and 37 are block diagrams illustrating the configuration of thedisplay device that has been previously studied by the presentinventors. Here, the case of using a drive electrode as the magneticfield generation coil will be described as similar to FIG. 7.

In FIGS. 36 and 37, TL(n) to TL(n+5) represent the drive electrodes. Inaddition, each of USR(n) to USR(n+5) and USL(n) to USL(n+5) represents aunit drive circuit. In FIGS. 36 and 37, VCOM represents a voltage wiringthat supplies the ground voltage Vss; TSV represents a signal wiringthat supplies a drive signal TSVCOM with a periodically changingvoltage; and CNR and CNL represent signal wirings which connect thedrive electrodes to each other in the magnetic field generation periodTGT.

In FIGS. 36 and 37, SL11 to SL13, SL21 to SL23, SL31 to SL33, SL41 toSL43, and SL51 to SL53 and SL61 to SL63 represent switches. The switchesSL11 to SL13 are provided as a set of a first switch group andcorrespond to the drive electrode TL(n). Similarly, the switches SL21 toSL23 are provided as a set of the first switch group and correspond tothe drive electrode TL(n+1); the switches SL31 to SL33 are provided as aset of the first switch group and correspond to the drive electrodeTL(n+2); and the switches SL41 to SL43 are provided as a set of thefirst switch group and correspond to the drive electrode TL(n+3). Inaddition, the switches SL51 to SL53 are provided as a set of the firstswitch group and correspond to the drive electrode TL(n+4); and theswitches SL61 to SL63 are provided as a set of the first switch groupand correspond to the drive electrode TL(n+5).

The switches SL11, SL21, SL31, SL41, SL51 and SL61 among the switchesforming the respective first switch groups are used as first switches,and each of the first switches is connected to the signal wiring TSV andone end portion of the corresponding drive electrode. In addition, theswitches SL12, SL22, SL32, SL42, SL52 and SL62 among the switchesforming the first switch groups are used as second switches, and each ofthe second switches is connected to the voltage wiring VCOM and one endportion of the corresponding drive electrode. Further, the switchesSL13, SL23, SL33, SL43, SL53 and SL63 among the switches forming thefirst switch groups are used as third switches, and each of the thirdswitches is connected to the signal wiring CNL and one end portion ofthe corresponding drive electrode.

In FIGS. 36 and 37, SR11 to SR13, SR21 to SR23, SR31 to SR33, SR41 toSR43, SR51 to SR53 and SR61 to SR63 also represent switches. Theswitches SR11 to SR13 are provided as a set of a second switch group andcorrespond to the drive electrode TL(n). Similarly, the switches SR21 toSR23 are provided as a set of the second switch group and correspond tothe drive electrode TL(n+1); the switches SR31 to SR33 are provided as aset of the second switch group and correspond to the drive electrodeTL(n+2); and the switches SR41 to SR43 are provided as a set of thesecond switch group and correspond to the drive electrode TL(n+3). Inaddition, the switches SR51 to SR53 are provided as a set of the secondswitch group and correspond to the drive electrode TL(n+4); and theswitches SR61 to SR63 are provided as a set of the second switch groupand correspond to the drive electrode TL(n+5).

Here, the switches SR11, SR21, SR31, SR41, SR51 and SR61 among theswitches forming the respective second switch groups are used also asfirst switches, and each of the first switches is connected to thesignal wiring TSV and the other end portion of the corresponding driveelectrode. In addition, the switches SR12, SR22, SR32, SR42, SR52 andSR62 among the switches forming the second switch groups are used assecond switches, and each of the second switches is connected to thevoltage wiring VCOM and the other end portion of the corresponding driveelectrode. Further, the switches SR13, SR23, SR33, SR43, SR53 and SR63among the switches forming the second switch groups are used as thirdswitches, and each of the third switches is connected to the signalwiring CNL and the one end portion of the corresponding drive electrode.

Each of the unit drive circuits USL(n) to USL(n+5) corresponds to eachof the drive electrodes TL(n) to TL(n+5), and each of the unit drivecircuits USR(n) to USR(n+5) also corresponds to each of the driveelectrodes TL(n) to TL(n+5). Each of the unit drive circuits USL(n) toUSL(n+5) and USR(n) to USR(n+5) controls the first switch group and thesecond switch group so that the magnetic field and the electric fieldare generated around the corresponding drive electrode at each time ofmagnetic field touch detection and electric field touch detection.

That is, in the case of generating the magnetic field in thecorresponding drive electrode, the first switch group and the secondswitch group are controlled so that two drive electrodes, which arearranged with the corresponding drive electrode sandwiched therebetween,are selected. The coil is configured using the two selected driveelectrodes, and the corresponding drive electrode is arranged at aninner side of the coil. Accordingly, the strong magnetic field isgenerated in the area of the corresponding drive electrode. On the otherhand, in the case of generating the electric field around thecorresponding drive electrode, the first switch group and the secondswitch group are controlled so that the corresponding drive electrode isselected.

<<Magnetic Field Touch Detection>>

A description will be given regarding an operation in a case ofgenerating a magnetic field in an area of the drive electrode TL(n+2) atthe time of magnetic field touch detection as follows. The driveelectrodes TL(n+1) and TL(n+3) are drive electrodes that sandwich thedrive electrode TL(n+2). The unit drive circuits USL(n+2) and USR(n+2),which correspond to the drive electrode TL(n+2), control the firstswitch groups (SL21, SL22, SL23) and (SL41, SL42, SL43) and the secondswitch groups (SR21, SR22, SR23) and (SR41, SR42, SR43). The respectivefirst and second switch groups correspond to the drive electrodesTL(n+1) and TL(n+3) that sandwich the drive electrode TL(n+2).

That is, the unit drive circuit USL(n+2) turns the first switch SL21 andthe second switch SL42 in the first switch groups (SL21, SL22, SL23) and(SL41, SL42, SL43) into an on-state (conductive state) and the remainingswitches into an off-state (non-conductive state). In addition, the unitdrive circuit USR(n+2) turns the third switches SR23 and SR43 in thesecond switch groups (SR21, SR22, SR23) and (SR41, SR42, SR43) into theon-state (conductive state) and the remaining switches into theoff-state (non-conductive state).

Accordingly, one end portion of the drive electrode TL(n+1) is connectedto the signal wiring TSV via the first switch SL21, and the other endportion of the drive electrode TL(n+1) is connected to the signal wiringCNR via the third switch SR23 as illustrated in FIG. 36. In addition,the one end portion of the drive electrode TL(n+3) is connected to thevoltage wiring VCOM via the second switch SL42, and the other endportion of the drive electrode TL(n+3) is connected to the signal wiringCNR via the third switch SR43. As a result, the respective other endportions of the drive electrodes TL(n+1) and TL(n+3), which are arrangedin parallel to the drive electrode TL(n+2) sandwiched therebetween, areelectrically connected via the signal wiring CNR, thereby forming thecoil having the drive electrode TL(n+2) at the inner side thereof.

In the case of the magnetic field touch detection, the ground voltageVss is supplied to the voltage wiring VCOM, and the drive signal TSVCOMwith the periodically changing voltage is supplied to the signal wiringTSV in the magnetic field generation period TGT. Accordingly, the drivesignal TSVCOM is supplied to the one end portion of the drive electrodeTL(n+1) as the magnetic field drive signal via the first switch SL21,and the ground voltage Vss is supplied to the one end portion of thedrive electrode TL(n+3) via the second switch SL42. Accordingly, themagnetic field is generated by the magnetic field generation coilconfigured by the drive electrodes TL(n+1) and TL(n+3), and the strongmagnetic field is formed around the drive electrode TL(n+2).

In FIG. 36, arrows I1, 12 indicate currents flowing to the driveelectrodes TL(n+1) and TL(n+3) by the drive signal TSVCOM and directionsthereof. When the current I1 flows, the drive electrode TL(n+1)generates a magnetic field in a direction indicated by a broken-linearrow ϕI1. The direction of the current I2 flowing to the driveelectrode TL(n+3) is exactly opposite to the direction of the currentI1, and thus the drive electrode TL(n+3) generates a magnetic field in adirection indicated by a broken-line arrow ϕI2. The magnetic fieldgenerated by the drive electrode TL(n+1) and the magnetic fieldgenerated by the drive electrode TL(n+3) are superimposed on each otheraround the drive electrode TL(n+2), thereby generating the strongmagnetic field.

Incidentally, the first switch, the second switch, and the third switchin the first switch group and the second switch group, except for thefirst switch groups (SL21, SL22, SL23) and (SL41, SL42, SL43) and thesecond switch groups (SR21, SR22, SR23) and (SR41, SR42, SR43) describedabove, are turned into the off-state by the unit drive circuits exceptfor the above-described unit drive circuits USL(n+2) and USR(n+2).

The unit drive circuits USL(n) to USL(n+5) are connected in series andeach have a function of operating as a shift register. Similarly, theunit drive circuits USR(n) to USR(n+5) are also connected in series andeach have a function of operating as the shift register. Selectioninformation to select the drive electrode which generates the magneticfield is set to, for example, the unit drive circuits USL(n) and USR(n),and the selection information is sequentially shifted toward the unitdrive circuits USL(n+5) and USR(n+5). The unit drive circuits at whichthe selection information arrive control the first switch group and thesecond switch group as described above, and perform the control so thatthe magnetic field is generated around the corresponding driveelectrode. That is, FIG. 36 illustrates a state where the selectioninformation arrives at the unit drive circuits USL(n+2) and USR(n+2).

FIG. 37 illustrates a state where the selection information arrives atthe unit drive circuits USL(n+3) and USR(n+3) by the shift operation. Anoperation at the time when the selection information arrives at the unitdrive circuits USL(n+3) and USR(n+3) is the same as the operationdescribed with reference to FIG. 36, and thus will not be described.

In this manner, the drive electrode, which generates the strong magneticfield, is sequentially changed (moved) as the selection information isshifted.

<<Electric Field Touch Detection>>

Next, a description will be given regarding an operation in a case ofelectric field touch detection. Here, the description will be also givenby exemplifying the drive electrode TL(n+2).

In the electric field touch detection, the unit drive circuits USL(n+2)and USR(n+2) control the first switch group and the second switch groupwhich are different from those in the case of the magnetic field touchdetection. That is, the first switch group (SL31, SL32, SL33) and thesecond switch group (SR31, SR32, SR33), which are connected to thecorresponding drive electrode TL(n+2) that corresponds to the unit drivecircuits USL(n+2) and USR(n+2), are controlled. In this case, the firstswitch SL31 in the first switch group (SL31, SL32, SL33) and the firstswitch SR31 in the second switch group (SR31, SR32, SR33) are turnedinto the on-state, and the second switches SL32 and SR32 and the thirdswitches SL33 and SR33 are turned into the off-state.

The drive signal TSVCOM with the periodically changing voltage issupplied to the signal wiring TSV even in the electric field touchdetection. Thus, the drive signal TSVCOM is supplied to the driveelectrode TL(n+2) as the electric field drive signal from both endportions thereof via the first switches SL31 and SR31. At this time, thefirst switch, the second switch, and the third switch in the remainingfirst switch group and second switch group are turned in the off-state.Thus, the drive electrodes TL(n) to TL(n+1) and TL(n+3) to TL(n+5) arein a floating state.

When the selection information is shifted to the unit drive circuitsUSL(n+3) and USR(n+3) from the unit drive circuits USL(n+2) and USR(n+2)by the shift operation, the unit drive circuits USL(n+3) and USR(n+3)controls the first switch group and the second switch group, which areconnected to the corresponding drive electrode TL(n+3), in the samemanner as above. Accordingly, the drive signal TSVCOM is supplied to thedrive electrode TL(n+3) as the electric field drive signal.

<<Problem>>

In the case of the magnetic field touch detection, it is required forforming the magnetic field generation coil that a plurality of driveelectrodes arranged in parallel to each other are connected to thesignal wiring (CNR or CNL) and the third switch, as described above. Inaddition, a switch group, which is connected to a drive electrodedifferent from a drive electrode arranged in a generating area of astrong magnetic field, is controlled in this case. On the contrary, aswitch group, which is connected to a drive electrode arranged in agenerating area of an electric field, is controlled in the case of theelectric field touch detection. Thus, a problem that the control becomescomplicated occurs. Further, there arises a problem of an increase inthe occupied area of the drive circuit (control circuit) that performsthe control.

<Overall Configuration of Display Device>

FIG. 8 is a block diagram illustrating the configuration of the displaydevice 1 according to the first embodiment. Here, a description will begiven by exemplifying a case where the display device 1 is a liquidcrystal display device although not particularly limited thereto. InFIG. 8, the display device 1 is provided with a display panel (liquidcrystal panel) 2, a signal line selector 3, a display control device 4,a gate driver 5, and a touch control device 6. In addition, the displaydevice 1 is provided with selection drive circuits (a first drivecircuit and a second drive circuit) SSR and SSL, a switching regulatorcircuit SCX, and an amplifier circuit AMP. These devices and circuitsprovided in the display device 1 will be described later in detail, andso the overall overview will be described here.

The display panel 2 includes a pixel array LCD in which a plurality ofpixels are arranged in a matrix form although will be described laterwith reference to FIG. 12. A plurality of signal lines, a plurality ofdrive electrodes, and a plurality of scan lines are arranged in thepixel array LCD. Here, the signal lines are arranged in respectivecolumns of the pixel array LCD; the drive electrodes are arranged inrows of the pixel array LCD; and the plurality of scan lines arearranged in the respective rows of the pixel array LCD. When thedescription is given with reference to FIG. 8, the signal wirings extendin the vertical direction (column direction) and are arranged inparallel in the horizontal direction (row direction). Further, the driveelectrodes extend in the horizontal direction and are arranged inparallel in the vertical direction. Further, the scan lines extend inthe horizontal direction and are arranged in parallel in the verticaldirection. In this case, the pixel is arranged in a portion at which thesignal line and the scan line cross each other. The pixel is selected bythe signal line and the scan line; a voltage of the signal line and avoltage (display drive signal) of the drive electrode at the time areapplied to the selected pixel; and the selected pixel performs displayaccording to a voltage gap between the signal line and the driveelectrode in a period for the display (display period).

The display control device 4 is provided with a control circuit D-CNTand a signal line driver D-DRV. The control circuit D-CNT receives atiming signal supplied to an external terminal Tt, and image informationsupplied to an input terminal Ti; forms an image signal Sn according tothe image information supplied to the input terminal Ti; and suppliesthe image signal Sn to the signal line driver D-DRV. The signal linedriver D-DRV supplies the supplied image signal Sn to the signal lineselector 3 in a time division manner in the display period. Further, thecontrol circuit D-CNT receives the timing signal supplied to theexternal terminal Tt, and a control signal SW sent from the touchcontrol device 6; and forms various types of control signals. Thecontrol signal to be formed by the control circuit D-CNT includes:selection signals SEL1 and SEL2 supplied to the signal line selector 3;a synchronization signal TSHD; a clock signal CLK; a magnetic fieldenable signal SC_EN; an electric field enable signal TC_EN; the drivesignal TSVCOM; a control signal Y-CNT relating to the touch detection; aclock signal CLK; and the like.

Among the signals to be formed by the control circuit D-CNT, themagnetic field enable signal SC_EN is an enable signal indicatingimplementation of the magnetic field touch detection, and the electricfield enable signal TC-EN is an enable signal indicating implementationof the electric field touch detection. In addition, the synchronizationsignal TSHD is a synchronization signal which identifies the period(display period), in which the display is performed in the display panel2, and the period (touch detection period), in which the touch detection(the magnetic field touch detection and the electric field touchdetection) is performed. The drive signal TSVCOM is a signal whosevoltage periodically changes and which is supplied to the driveelectrode as the magnetic field drive signal or the electric field drivesignal in the touch detection period.

The signal line driver D-DRV supplies the image signal Sn to the signalline selector 3 in a time division manner according to the selectionsignals SEL1 and SEL2 in the display period. The signal line selector 3is connected to the plurality of signal lines arranged in the displaypanel 2, and supplies the supplied image signal to a suitable signalline according to the selection signals SEL1 and SEL2 in the displayperiod. The gate driver 5 forms scan line signals Vs0 to Vsp accordingto the timing signal sent from the control circuit D-CNT, and suppliesthe scan line signal to a scan line inside the display panel 2 in thedisplay period. In the display period, a pixel, which is connected to ascan line to which a high-level scan line signal is supplied, isselected, and the selected pixel performs display according to the imagesignal supplied to the signal line at the time, thereby performing thedisplay.

The touch control device 6 is provided with a detection circuit DETwhich receives sense signals S(0) to S(p); a processing circuit PRSwhich processes a detection signal DET-D sent from the detection circuitDET to extract a coordinate of a touched position; and a control circuitT-CNT. The control circuit T-CNT receives the synchronization signalTSHD, the magnetic field enable signal SC_EN, and the electric fieldenable signal TC_EN from the display control device 4, and performscontrol so that the touch control device 6 operates in synchronizationwith the display control device 4.

That is, the control circuit T-CNT performs control so that thedetection circuit DET and the processing circuit PRS operate when thesynchronization signal TSHD, the magnetic field enable signal SC_EN, andthe electric field enable signal TC_EN indicate the touch detection. Inaddition, the control circuit T-CNT receives the detection signal fromthe detection circuit DET, forms the control signal SW, and supplies thecontrol signal to the control circuit D-CNT. The processing circuit PRSoutputs the extracted coordinate from an external terminal To ascoordinate information.

The display panel 2 has sides 2-U and 2-D, which are parallel to the rowof the pixel array LCD, and sides 2-R and 2-L which are parallel to thecolumn of the pixel array LCD. Here, the side 2-U and the side 2-D aresides opposing each other, and are arranged so that the plurality ofdrive electrodes and the plurality of scan lines in the pixel array LCDare sandwiched between the two sides. In addition, the side 2-R and theside 2-L are also sides opposing each other and are arranged so that theplurality of signal lines in the pixel array LCD are sandwiched betweenthese two sides.

The selection drive circuit SSR is arranged along the side 2-R of thedisplay panel 2, and the selection drive circuit SSL is arranged alongthe side 2-L of the display panel 2. The selection drive circuit SSR iscoupled with the plurality of drive electrodes arranged on the displaypanel 2 on the side 2-R of the display panel 2 side, and the selectiondrive circuit SSL is coupled with the plurality of drive electrodesarranged on the display panel 2 on the side 2-L of the display panel 2side. That is, the selection drive circuits SSR and SSL are connected tothe drive electrode arranged on the display panel 2 outside the displaypanel 2.

The selection drive circuit SSR is provided with a drive circuit SR-Rand a selection circuit SR-C. The drive circuit SR-R is provided with ashift register having a plurality of shift stages, and selectioninformation SEI is set to the shift register by the control signalY-CNT. The set selection information SEI is sequentially shifted insynchronization with the clock signal CLK.

When the magnetic field touch detection is designated by the magneticfield enable signal SC_EN, the drive circuit SR-R forms and outputs aselection signal according to the selection information stored in theshift register. Although not particularly limited, the drive circuitSR-R forms two selection signals according to the selection informationwhen the magnetic field touch detection is designated in the firstembodiment. On the other hand, when the electric field touch detectionis designated by the electric field enable signal TC_EN, the drivecircuit SR-R also forms and outputs a selection signal according to theselection information stored in the shift register. Although notparticularly limited, the drive circuit SR-R forms one selection signalaccording to the selection information when the electric field touchdetection is designated in the first embodiment.

The selection circuit SR-C receives the selection signal from the drivecircuit SR-R and connects the drive electrode, which is designated bythe selection signal, to the signal wiring (magnetic field drive signalwiring) TSV and the voltage wiring (reference signal wiring) VCOM. Thatis, the drive electrode, which is designated by one selection signalfrom between the two selection signals, is connected to the signalwiring TSV, and the drive electrode designated by the other selectionsignal is connected to the voltage wiring VCOM at the time of magneticfield touch detection. On the other hand, the drive electrode designatedby the single selection signal is connected to the signal wiring TSV atthe time of electric field touch detection.

In the first embodiment, the ground voltage Vss is supplied to thevoltage wiring VCOM at the time of magnetic field touch detection. Inaddition, the drive signal TSVCOM with the periodically changing voltageis supplied to the signal wiring TSV at each time of magnetic fieldtouch detection and electric field touch detection. Thus, the drivesignal TSVCOM is supplied to the drive electrode, which is designated byone selection signal from between the two selection signals, as themagnetic field drive signal via the selection circuit SR-C at the timeof magnetic field touch detection. At this time, the ground voltage Vssis supplied to the drive electrode designated by the other selectionsignal via the selection circuit SR-C.

In addition, the drive signal TSVCOM is supplied to the drive electrode,which is designated by the selection signal, as the electric field drivesignal via the selection circuit SR-C at the time of electric fieldtouch detection.

The selection drive circuit SSL has the same configuration as theselection drive circuit SSR. That is, the selection drive circuit SSL isprovided with a drive circuit SL-R and a selection circuit SL-C. Thedrive circuit SL-R is provided with a shift register having a pluralityof shift stages, and the selection information SEI is set to the shiftregister by the control signal Y-CNT. The set selection information issequentially shifted in synchronization with the clock signal CLK.

When the magnetic field touch detection is designated by the magneticfield enable signal SC_EN, the drive circuit SL-R forms and outputs aselection signal according to the selection information stored in theshift register. The drive circuit SL-R forms two selection signalsaccording to the selection information when the magnetic field touchdetection is designated. On the other hand, when the electric fieldtouch detection is designated by the electric field enable signal TC_EN,the drive circuit SL-R also forms and outputs a selection signalaccording to the selection information stored in the shift register.However, the drive circuit SR-R forms one selection signal according tothe selection information when the electric field touch detection isdesignated.

The selection circuit SL-C receives the selection signal from the drivecircuit SL-R and connects the drive electrode, which is designated bythe selection signal, to the signal wiring TSV and the voltage wiringVCOM. That is, the drive electrode, which is designated by one selectionsignal from between the two selection signals, is connected to thevoltage wiring VCOM, and the drive electrode designated by the otherselection signal is connected to the signal wiring TSV at the time ofmagnetic field touch detection. On the other hand, the drive electrodedesignated by the single selection signal is connected to the signalwiring TSV at the time of electric field touch detection.

Accordingly, the ground voltage Vss is supplied to the drive electrode,which is designated by the one selection signal from between the twoselection signals via the selection circuit SL-C at the time of magneticfield touch detection. At this time, the drive signal TSVCOM is suppliedto the drive electrode, which is designated by the other selectionsignal, as the magnetic field drive signal via the selection circuitSL-C.

In addition, the drive signal TSVCOM is supplied to the drive electrode,which is designated by the selection signal, as the electric field drivesignal via the selection circuit SL-C at the time of electric fieldtouch detection.

The selection drive circuit SSR and the selection drive circuit SSL areconfigured to operate in synchronization with each other. Although notparticularly limited, the selection drive circuits SSR and SSL areconfigured to operate in a synchronized manner as the same clock signalCLK is supplied to the selection drive circuits SSR and SSL, and thesame control signal Y-CNT is supplied to the selection drive circuitsSSR and SSL in the first embodiment.

At the time of magnetic field touch detection, the drive electrodedesignated by the selection information in the selection drive circuitSSR is set to be the same as the drive electrode designated by theselection information in the selection drive circuit SSL. In otherwords, two drive electrodes among the plurality of drive electrodes aredesignated by the selection drive circuits SSR and SSL, respectively, atthe time of magnetic field touch detection. In this case, the driveelectrode, which is connected to the voltage wiring VCOM in theselection circuit SR-C, is connected to the signal wiring TSV in theselection circuit SL-C. In addition, the drive electrode, which isconnected to the signal wiring TSV in the selection circuit SR-C, isconnected to the voltage wiring VCOM in the selection circuit SL-C.

Accordingly, a current depending on a voltage change of the magneticfield drive signal (the drive signal TSVCOM) flows in each of the twodesignated drive electrodes, and the magnetic field is generated aroundeach of the drive electrodes. In addition, directions of the respectivecurrents are directly opposite to each other, and thus the magneticfields formed by the respective drive electrodes are superimposed oneach other in an area sandwiched by the two drive electrodes, therebyforming a strong magnetic field.

In addition, the same drive electrode is connected to the signal wiringTSV in each of the selection circuits SR-C and SL-C at the time ofelectric field touch detection. Thus, the electric field drive signal(the drive signal TSVCOM) is supplied to the designated drive electrodefrom both end portions thereof, and the electric field depending on thevoltage change of the electric field drive signal is generated.

The switching regulator circuit SCX is arranged along the side 2-U ofthe display panel 2, and the switching regulator circuit SCX is coupledwith the plurality of signal lines arranged in the display panel 2 onthe side 2-U side. That is, the switching regulator circuit SCX isconnected to the plurality of signal lines outside the display panel 2.Further, the amplifier circuit AMP is coupled with the plurality ofsignal lines arranged in the display panel 2 via the signal lineselector 3 arranged along the side 2-D of the display panel 2.

When the magnetic field touch detection is designated by the magneticfield enable signal SC_EN, the switching regulator circuit SCXelectrically connects predetermined signal lines arranged in the displaypanel 2 to each other. Accordingly, the signal lines, which is arrangedin parallel to each other, are connected to each other on the side 2-Uside, and thus a plurality of coils each of which has a one-turn windingusing the signal line as a winding are formed. Each end portion of theplurality of coils is connected to the amplifier circuit AMP via thesignal line selector 3 on the side 2-D side. The coil with the one-turnwinding functions as the magnetic field detection coil. That is, asignal change is generated in the magnetic field detection coilconfigured using the signal line depending on the magnetic fieldgenerated by the pen in the magnetic field detection period TDT (FIGS.2A and 2B). This signal change is supplied to the amplifier circuit AMP,amplified, outputted as the sense signals S(0) to S(p), and supplied tothe detection circuit DET.

In addition, since the signal lines are not connected to each other viathe switching regulator circuit SCX at the time of electric field touchdetection, the amplifier circuit AMP amplifies the signal change of thesignal line, which changes depending on presence or absence of touch bythe finger, and supplies the amplified signal change to the detectioncircuit DET as the sense signals S(0) to S(p).

The detection circuit processes the supplied sense signals S(0) to S(p)and supplies the processed sense signals to the processing circuit PRS.Accordingly, the presence or absence of touch by the finger, acoordinate of the touch, the pen pressure, and the like are obtained bythe processing circuit PRS and outputted from the external terminal Toat the time of magnetic field touch detection. In addition, the presenceor absence of touch by the finger, the coordinate of the touch, and thelike are obtained by the processing circuit PRS and outputted from theexternal terminal To at the time of electric field touch detection.

The description has been given regarding the case where the magneticfield detection coil has the one-turn winding herein, the invention isnot limited thereto. However, three or more signal lines may beconnected in series by providing the same function as the switchingregulator circuit SCX in the amplifier circuit AMP to form a coil whichhas a winding with one and half turns or more.

<Module Configuration of Display Device 1>

FIG. 9 is a schematic plan view illustrating an overall configuration ofa module 900 to which the display device 1 is mounted. FIG. 9 is drawnin accordance with actual arrangement although being schematic. In FIG.9, reference numeral 901 represents an area in the TFT glass substrateTGB illustrated in FIGS. 4A and 4B, and reference numeral 902 representsan area having the TFT glass substrate TGB and the CF glass substrateCGB illustrated in FIGS. 4A and 4B. The TFT glass substrate TGB isintegrated with the module 900. That is, the TFT glass substrate TGB iscommon to the area 901 and the area 902, and the CF glass substrate CGBand the like is further formed on an upper surface of the TFT glasssubstrate TGB in the area 902 as illustrated in FIGS. 4A and 4B.

In FIG. 9, numeral 900-U represents a short side of the module 900, andnumeral 900-D represents a side of the module 900, that is, a short sideopposing the short side 900-U. Further, numeral 900-L represents a longside of the module 900, and numeral 900-R represents a side of themodule 900, that is, a long side opposing the long side 900-L.

The gate driver 5 and the selection drive circuit SSL illustrated inFIG. 8 are arranged in an area sandwiched between the side 2-L of thedisplay panel 2 and the long side 900-L of the module 900 in the area902. In addition, the selection drive circuit SSR illustrated in FIG. 8is arranged in an area sandwiched between the side 2-R of the displaypanel 2 and the long side 900-R of the module 900 in the area 902. Theswitching regulator circuit SCX illustrated in FIG. 8 is arranged in anarea sandwiched between the side 2-U of the display panel 2 and theshort side 900-U of the module 900.

In addition, the signal line selector 3, the amplifier circuit AMP, anda drive semiconductor device DDIC illustrated in FIG. 8 are arranged inan area sandwiched between the side 2-D of the display panel 2 and theshort side 900-D of the module 900.

In the first embodiment, the signal line driver D-DRV and the controlcircuit D-CNT illustrated in FIG. 8 are built in a single semiconductordevice. In the present specification, this single semiconductor deviceis illustrated as the drive semiconductor device DDIC. Further, thetouch control device 6 illustrated in FIG. 8 is also built in the singlesemiconductor device. In the present specification, the semiconductordevice with the built-in touch control device 6 is referred to also as atouch semiconductor device 6 to be distinguished from the drivesemiconductor device DDIC. Of course, each of the drive semiconductordevice DDIC and the touch semiconductor device 6 may be configured usinga plurality of semiconductor devices. In addition, the amplifier circuitAMP may be built in the drive semiconductor device DDIC, for example.

In the first embodiment, the amplifier circuit AMP is arranged in thearea 901 and is configured by wirings and parts formed on the TFT glasssubstrate TGB in the area 901. The part includes, for example, a thinfilm transistor (hereinafter, referred to also as the TFT transistor).In addition, the drive semiconductor device DDIC is mounted to the TFTglass substrate so as to cover the amplifier circuit AMP when seen in aplan view. Accordingly, it is possible to suppress an increase of alower frame of the display panel 2.

In addition, parts forming the selection drive circuits SSL and SSR andthe switching regulator circuit SCX are also formed on the TFT glasssubstrate TGB in the area 902.

In FIG. 9, numerals FB1 and FB2 represent flexible cables. Although notparticularly limited, the touch semiconductor device 6 is mounted to theflexible cable FB1, and a connector CN is mounted to the flexible cableFB2. The sense signals S(0) to S(p) described in FIG. 8 are suppliedfrom the amplifier circuit AMP to the touch semiconductor device 6 viathe connector CN. Further, transmission and reception of signals areperformed between the touch semiconductor device 6 and the drivesemiconductor device DDIC via the connector CN. The synchronizationsignal TSHD is drawn in FIG. 9 as an example of the signal to betransmitted and received.

As already described above, the display panel 2 includes the pixel arrayin which the plurality of pixels are arranged in the matrix form. Thepixel array is provided with the plurality of drive electrodes TL(0) toTL(p) and the scan lines GL(0) to GL(p) arranged along the row of thearray, and the plurality of signal lines SL(0) to SL(p) arranged alongthe column of the array. FIG. 9 illustrates two drive electrodes TL(n)and TL(m) and two signal lines SL(k) and SL(n), for example.Incidentally, FIG. 9 does not illustrate the scan line. The pixel isarranged at each crossing portion of the signal lines SL(0) to SL(p) andthe scan lines or the drive electrodes TL(0) to TL(p). Reference signsR, G and B, which are indicated on the four sides of the display panel 2illustrated in FIG. 9, represent pixels corresponding to three primarycolors.

FIG. 10 is a plan view illustrating a relationship between the driveelectrode and the signal line provided in the display panel 2. Althoughthe display panel 2 includes the drive electrodes TL(0) to TL(p) and thesignal lines SL(0) to SL(p), some of the drive electrodes and the signallines are exemplified as drive electrodes TL(n−6) to TL(n+9) and signallines SL(n−6) to SL(n+9) in FIG. 10. Incidentally, FIG. 10 does notillustrate the scan line.

When the drive electrode is described by exemplifying the driveelectrodes TL(n−6) to TL(n+9) illustrated in FIG. 10, each of the driveelectrodes includes a first electrode and a plurality of secondelectrodes connected to the first electrode. Here, the first electrodeis, for example, a transparent electrode, and the second electrode is anelectrode which has a lower sheet resistance than the first electrode.In FIG. 10, one second electrode among the plurality of secondelectrodes, which are provided in each of the drive electrodes, isillustrated as an auxiliary electrode SM. Incidentally, reference signSM is attached to only the auxiliary electrodes provided in the driveelectrodes TL(n−6) and TL(n+9) in FIG. 10 to prevent the drawing frombeing complicated.

The auxiliary electrode SM also extends in the row direction of thearray, similarly to the first electrode (transparent electrode) formingthe drive electrode, and is electrically connected to the firstelectrode. Accordingly, reduction of combined resistance (impedance) ofthe drive electrode, which is provided with the first electrode and theauxiliary electrode (second electrode), is achieved. In the presentspecification, the first electrode (transparent electrode) and thesecond electrode (auxiliary electrode SM) connected to the firstelectrode are collectively referred to as the drive electrode unlessotherwise specified.

<Structure of Display Panel>

FIG. 11 is a cross-sectional view illustrating a configuration of thedisplay panel 2 included in the display device 1 according to the firstembodiment. When seen from the viewpoint of display, an area (firstarea) inside the display panel 2 is an area which is active (activearea) and is a display area where the display is performed. On the otherhand, an area (second area) outside the display panel 2 is an area wherethe display is not performed, and can be regarded as an area which isnon-active (non-active area) or a peripheral area. When the descriptionis given by exemplifying FIG. 9, the active area is an area surroundedby the sides 2-U, 2-D, 2-R and 2-L of the display panel 2.

FIG. 11 illustrates an A-A′ cross section of the display panel 2illustrated in FIG. 9. In this first embodiment, one color pixel isdisplayed using three pixels corresponding, respectively, to the threeprimary colors of R(red), G (green) and B (blue) in order to performcolor display. That is, the one color pixel can be regarded as beingconfigured using three subpixels. In this case, a signal line thattransfers a color image signal in the display period is configured usingthree signal lines. FIG. 11 illustrates the example of performing colordisplay to illustrate a specific structure of the display panel 2.

Reference signs of the signal lines used in FIG. 11 will be describedprior to describing FIG. 11. Each of the signal lines SL(0) to SL(p)represents the signal line that transfers the color image signal in thedisplay period. Each of the signal lines includes three signal linesthat transfer the image signal to three subpixels. FIG. 11 distinguishesthe three signal lines by attaching an alphabetical character of thecorresponding subpixel next to the reference sign of the signal line.When the signal line SL(n) is exemplified, the signal line SL(n)includes signal lines SL(n)R, SL(n)G and SL(n)B. Here, the alphabeticalcharacter R attached next to the reference sign SL(n) represents thesignal line that transfers the image signal to the subpixelcorresponding to the red (R) of the three primary colors in the displayperiod. The alphabetical character G attached next to the reference signSL(n) represents the signal line that transfers the image signal to thesubpixel corresponding to the green (G) of the three primary colors. Thealphabetical character B attached next to the reference sign SL(n)represents the signal line that transfers the image signal to thesubpixel corresponding to the blue (B) of the three primary colors.

In FIG. 11, numeral 1100 represents a TFT glass substrate (TGB in FIGS.4A and 4B). A first wiring layer (metal wiring layer) 1101 is formed onthe TFT glass substrate 1100. A scan line GL(n) is configured using awiring formed on the first wiring layer 1101. An insulating layer 1102is formed on the first wiring layer 1101, and second wiring layers(metal wiring layers) 1103 are formed on the insulating layer 1102. Thesignal lines SL(n)R, SL(n)G and SL(n)B, signal lines SL(n+1)R, SL(n+1)Gand SL(n+1)B and signal lines SL(n+2)R and SL(n+2)G are configured usingthe wirings formed in the second wiring layers 1103. In FIG. 11, inorder to indicate that these signal lines are configured by the secondwiring layers 1103, reference numeral 1103 representing the secondwiring layer is described in [ ] next to the reference signs of thesignal lines. For example, the signal line SL(n)G is indicated bySL(n)G[1103].

An insulating layer 1104 is formed on the second wiring layers 1103, anda third wiring layer (metal wiring layer) 1105 is formed on theinsulating layer 1104. The drive electrode TL(n) and the auxiliaryelectrode SM are configured using wirings formed on the third wiringlayer 1105. Here, the drive electrode TL(n) is the transparent electrode(first electrode). Further, the auxiliary electrode SM (secondelectrode) has a lower resistance value than the drive electrode TL(n),and is formed to be electrically connected to the drive electrode TL(n).A resistance value of the drive electrode TL(n), which is thetransparent electrode, is relatively high, but it is possible to reducethe combined resistance by electrically connecting the auxiliaryelectrode SM to the drive electrode TL(n). Here, [1105], which isattached to the reference signs of the drive electrode and the auxiliaryelectrode, also indicates that the electrodes are configured using thethird wiring layer 1105.

An insulating layer 1106 is formed on the third wiring layer 1105, andpixel electrodes LDP are formed on a top surface of the insulating layer1106. In FIG. 11, each reference sign of CR, CB and CG represents thecolor filter. A liquid crystal layer 1107 is sandwiched between thecolor filters CR (red), CG (green) and CB (blue) and the insulatinglayer 1106. Here, the pixel electrode LDP is provided at a crossingpoint between the scan line and the signal line, and the color filterCR, CG or CB corresponding to each of the pixel electrodes LDP isprovided above each of the point pixel electrodes LDP. A black matrix BMis provided among the respective color filters CR, CG and CB.

In addition, the CF glass substrate CGB is formed on the color filtersCR, CG and CB as illustrated in FIGS. 4A, 4B, 6A and 6B although notillustrated in FIG. 11. Further, the detection electrodes RL(0) to RL(p)and the polarizing plate are formed on the CF glass substrate CGB asillustrated in FIGS. 4A and 4B.

<Pixel Array>

Next, a description will be given regarding a circuit configuration ofthe display panel 2. FIG. 12 is a circuit diagram illustrating thecircuit configuration of the display panel 2 illustrated in FIGS. 8 and9. Also in FIG. 12, the signal line is represented in the same displayformat as that of FIG. 11. In FIG. 12, each one of a plurality ofreference signs SPix, which is illustrated by one-dot chain line,represents one liquid crystal display element (subpixel). The subpixelsSPix are arranged in a matrix form in the display panel 2, andconfigures a liquid crystal element array (the pixel array) LCD. Thepixel array LCD is provided with the plurality of scan lines GL(0) toGL(p) arranged in the respective rows and extending in the rowdirection, and the signal lines SL(0)R, SL(0)G, SL(0)B to SL(p)R, SL(p)Gand SL(p)B arranged in the respective columns and extending in thecolumn direction. In addition, the pixel array LCD includes the driveelectrodes TL(0) to TL(p) arranged in the respective rows and extendingin the row direction.

FIG. 12 illustrates only a part of the pixel array relating to scanlines GL(n−1) to GL(n+1), the signal lines SL(n)R, SL(n)G, SL(n)B toSL(n+1)R, SL(n+1)G and SL(n+1)B, and drive electrodes TL(n−1) toTL(n+1). To make the description easy in FIG. 12, the drive electrodesTL(n−1) to TL(n+1) is shown to be arranged in the respective rows, butone drive electrode may be arranged with respect to a plurality of rows.

Each of the subpixels SPix, which are arranged at crossing points amongthe row and the column of the pixel array LCD, is provided with a TFTtransistor Tr formed on the TFT glass substrate 1100 and a liquidcrystal element LC of which one terminal is connected to a source of theTFT transistor Tr. In the pixel array LCD, gates of the TFT transistorsTr of the plurality of subpixels SPix arranged in the same row areconnected to the scan line arranged in the same row, and drains of theTFT transistors Tr of the plurality of subpixels SPix arranged in thesame column are connected to the signal line arranged in the samecolumn. In other words, the plurality of subpixels SPix are arranged inthe matrix form; the scan lines are arranged in the respective rows; andthe plurality of subpixels SPix arranged in the corresponding row areconnected to the scan line. Further, the signal lines are arranged inthe respective columns, and the subpixels SPix arranged in thecorresponding column are connected to the signal line. Further, theother ends of the liquid crystal elements LC of the plurality ofsubpixels SPix arranged in the same row are connected to the driveelectrode arranged in the row.

When the description is given with the example illustrated in FIG. 12,the respective gates of the TFT transistors Tr of the plurality ofsubpixels SPix arranged on an uppermost row are connected to the scanline GL(n−1) arranged in the uppermost row in FIG. 12. Further, therespective drains of the TFT transistors Tr of the plurality ofsubpixels SPix arranged in a leftmost column are connected to the signalline SL(n)R arranged in the leftmost column in FIG. 12. Further, therespective other ends of the liquid crystal elements LC of the pluralityof subpixels SPix arranged in the uppermost row are connected to thedrive electrode TL(n−1) arranged in the uppermost row in FIG. 12.

As described above, the single subpixel SPix corresponds to one of thethree primary colors. Accordingly, the three primary colors of R, G andB are configured using the three subpixels SPix. In FIG. 12, one colorpixel Pix is formed using the three subpixels SPix, which aresuccessively arranged in the same row, and color is expressed by therelevant pixel Pix. That is, the subpixel SPix indicated by 1200R is setas a subpixel SPix(R) of R(red); the subpixel SPix indicated by 1200G isset as a subpixel SPix(G) of G (green); and the subpixel SPix indicatedby 1200B is set as a subpixel SPix(B) of B (blue) in FIG. 12.Accordingly, the color filter CR for red is provided as the color filterin the subpixel SPix(R) indicated by 1200R; the color filter CG forgreen is provided as the color filter in the subpixel SPix(G) indicatedby 1200G; and the color filter CB for blue is provided as the colorfilter in the subpixel SPix(B) indicated by 1200B.

Further, among the signals each of which indicates the single pixel, animage signal corresponding to R (red) is supplied from the signal lineselector 3 to the signal line SL(n)R; an image signal corresponding to G(green) is supplied from the signal line selector 3 to the signal lineSL(n)G; and an image signal corresponding to B (blue) is supplied fromthe signal line selector 3 to the signal line SL(n)B.

The TFT transistor Tr of each of the subpixels SPix is an N-channel TFTtransistor although not particularly limited thereto. Pulsed scan linesignals are supplied from the gate driver 5 (FIGS. 8 and 9) to the scanlines GL(0) to GL(p), which sequentially become high levels in thisorder. That is, voltages of the scan lines sequentially become highlevels from the scan line GL(0) arranged in the upper row toward thescan line GL(p) arranged in the lower row in the pixel array LCD.Accordingly, the TFT transistors Tr in the subpixels SPix aresequentially turned into the on-state (conductive state) from thesubpixel SPix arranged in the upper row toward the subpixel SPixarranged in the lower row in the pixel array LCD.

When the TFT transistor Tr is turned into the on-state, the image signalsupplied to the signal line is supplied to the liquid crystal element LCvia the TFT transistor that is in the conductive state at the time. Theelectric field of the liquid crystal element LC is changed depending ona gap voltage between a voltage of the display drive signal supplied tothe drive electrodes TL(0) to TL(p) and a voltage of the supplied imagesignal, and the modulation of light passing through the liquid crystalelement LC is changed. Accordingly, a color image, which corresponds tothe image signals supplied to the signal lines SL(0)R, SL(0)G, SL(n)B toSL(p)R, SL(p)G, and SL(p)B in synchronization with the scan line signalsupplied to the scan lines GL(0) to GL(p), is displayed on the displaypanel 2.

Each of the plurality of subpixels SPix can be regarded as including aselection terminal and a pair of terminals. In this case, the gate ofthe TFT transistor Tr configuring the subpixel SPix is the selectionterminal of the subpixel SPix; the drain of the TFT transistor Tr is oneterminal between the pair of terminals; and the other end of the liquidcrystal element LC is the other terminal of the subpixel SPix.

Here, a correspondence between the arrangement of the display panel 2illustrated in FIGS. 8 and 9 and the circuit diagram illustrated in FIG.12 will be described as follows.

The pixel array LCD includes a pair of sides substantially parallel tothe row of the array, and a pair of sides substantially parallel to thecolumn of the array. The pair of sides parallel to the row of the pixelarray LCD are a first side and a second side corresponding to the shortsides 2-U and 2-D of the display panel 2 illustrated in FIGS. 8 and 9;and the pair of sides parallel to the column of the pixel LCD are athird side and a fourth side corresponding to the long sides 2-L and 2-Rof the display panel 2.

As illustrated in FIG. 9, the signal line selector 3, the amplifiercircuit AMP, and the drive semiconductor device DDIC are arranged alongthe second side out of the pair of sides parallel to the row, that is,the short side 2-D of the display panel 2 in the pixel array LCD. Theimage signal from the drive semiconductor device DDIC is supplied to thesignal lines SL(0)R, SL(0)G, SL(0)B to SL(p)R, SL(p)G and SL(p)B via thesignal line selector 3 on the second side (the short side 2-D of thedisplay panel 2) in the pixel array LCD.

In addition, the switching regulator circuit SCX is arranged along thefirst side of the pixel array LCD, that is, the other side (the shortside 2-U) of the display panel 2 as illustrated in FIG. 9.

Further, the gate driver 5 and the selection drive circuit SSL arearranged along the third side out of the pair of sides parallel to thecolumn (the third side and the fourth side), that is, the long side 2-Lof the display panel 2 in the pixel array LCD. The scan line signal fromthe gate driver 5 is supplied to the scan lines GL(0) to GL(p) on thethird side in the pixel array LCD. Although the gate driver 5 isarranged along the long side 2-L of the display panel 2 in FIG. 9, thegate driver 5 may be divided into two parts to be arranged along thelong side 2-L (the third side of the pixel array LCD) and the long side2-R (the fourth side of the pixel array LCD), respectively. In addition,the display drive signal is supplied from the selection drive circuitSSL to the drive electrode on the third side in the pixel array LCD inthe display period. Further, the magnetic field drive signal or theelectric field drive signal is supplied from the selection drive circuitSSL to the designated drive electrode on the third side in the magneticfield generation period TGT for the magnetic field touch detection or atthe time of electric field touch detection.

The selection drive circuit SSR is arranged along the fourth side of thepixel array LCD, that is, the long side 2-R of the display panel 2 asillustrated in FIG. 9. In the display period, the display drive signalis supplied from the selection drive circuit SSR to the common electrodeon the fourth side. On the other hand, the magnetic field drive signalor the electric field drive signal is also supplied to the designateddrive electrode from the fourth side, similarly to the above-describedselection drive circuit SSL, at the time of the magnetic field touchdetection or electric field touch detection.

Although the pixel array LCD of a case where the color display isperformed in the display panel 2 has been described concretely, thepixel array LCD may be regarded as being configured by the plurality ofcolor pixels Pix (pixels) each of which is configured using the threesubpixels SPix. When regarded as above, the plurality of pixels Pix arearranged in a matrix form, thereby configuring the pixel array LCD. Thecorresponding scan lines GL(0) to GL(p) and the corresponding driveelectrodes TL(0) to TL(p) are arranged in the respective rows of thepixel array LCD configured by the pixels Pix, and the signal lines SL(0)to SL(p) are arranged in the respective columns thereof.

In this case, the three subpixels SPix are regarded as a single pixelPix, and the pixel Pix is regarded as having the same configuration asthe subpixel SPix. The respective selection terminals of the pixels Pixarranged in the matrix form in the pixel array LCD are connected to thescan lines GL(0) to GL(p) arranged in the same row as the pixels Pix;the respective one-side terminals of the pixels Pix are connected to thesignal lines SL(0) to SL(p) arranged in the same column; and therespective other-side terminals of the pixels Pix are connected to thedrive electrodes TL(0) to TL(p) arranged in the same column. Of course,one drive electrode may correspond to a plurality of columns of thepixel array LCD. In such a case, the other terminals of the pixels Pixarranged in the plurality of rows are connected to the common driveelectrode.

Even in the case where it is regarded that the pixel array LCD isregarded as being configured by the plurality of pixels Pix in thismanner, the correspondence between the arrangement of the display panel2 illustrated in FIGS. 8 and 9 and the circuit diagram illustrated inFIG. 12 is the same as the content that has been described above.

Although the description has been given with the case where the numberof the subpixels SPix configuring the single color pixel Pix is three,the number is not limited thereto. One color pixel may be configuredusing, for example, subpixels of white (W) and yellow (Y) in addition toR, G and B described above, or subpixels that additionally include anyone or a plurality of colors among complementary colors (cyan (C),magenta (M) and yellow (Y)) of R, G and B described above.

<Selection Drive Circuit>

Next, the configurations and operations of the selection drive circuitsSSL and SSR in the display device 1 according to the first embodimentwill be described with reference to FIGS. 13 to 18.

<<Overview of Operation of Selection Drive Circuit>>

First, the overview of the operation will be described in order tofacilitate the understanding of the selection drive circuit. In thefirst embodiment, the selection drive circuit SSR is provided with thedrive circuit SR-R and the selection circuit SR-C as illustrated in FIG.8. The drive circuit SR-R forms a selection signal to designate a driveelectrode which generates a strong magnetic field in the magnetic fieldgeneration period TGT for the magnetic field touch detection. Inaddition, the drive circuit SR-R forms a selection signal to designate adrive electrode which generates an electric field at the time ofelectric field touch detection. The selection circuit SR-C connectsdrive electrodes, which sandwich the designated drive electrode, to thesignal wiring TSV and the voltage wiring VCOM so that the magnetic fieldis generated around the drive electrode designated by the selectionsignal in the magnetic field generation period TGT. In addition, theselection circuit SR-C connects the drive electrode designated by theselection signal to the signal wiring TSV at the time of electric fieldtouch detection.

The drive circuit SR-R includes the plurality of unit drive circuitsUSR(0) to USR(p) each of which has the shift stage, and the shiftregister is configured by connecting the unit drive circuits USR(0) toUSR(p) in series. At each time of magnetic field touch detection andelectric field touch detection, the selection information, whichdesignates the drive electrode to be selected, is shifted in the shiftregister configured by the plurality of unit drive circuits, and so thedrive circuit SR-R forms the selection signals which sequentiallydesignate the drive electrodes.

The selection drive circuit SSL is also provided with the drive circuitSL-R and the selection circuit SL-C similarly to the selection drivecircuit SSR. The drive circuit SL-R includes the plurality of unit drivecircuits USL(0) to USL(p) similarly to the drive circuit SR-R, andoperates in the same manner as the drive circuit SR-R. In addition, theselection circuit SL-C operates in the same manner as the selectioncircuit SR-C.

FIG. 13 is an explanatory diagram illustrating a touch detectionoperation in the display device 1 according to the first embodiment.FIG. 13A illustrates a case where the touch detection operation is theelectric field touch detection, and FIG. 13B illustrates a case wherethe touch detection operation is the magnetic field touch detection.FIG. 13 illustrates the unit drive circuit USR(n) among the plurality ofunit drive circuits USR(0) to USR(p) forming the drive circuit SR-R andthe unit drive circuit USL(n) among the plurality of unit drive circuitsUSL(0) to USL(p) forming the drive circuit SL-R to describe the overviewof operation, and does not illustrate the selection circuits SR-C andSL-C.

Each of the unit drive circuits USR(0) to USR(p) and USL(0) to USL(p)corresponds to each of the drive electrodes TL(0) to TL(p) arranged tobe parallel to each other, but the unit drive circuits and the driveelectrodes may not necessarily have one-to-one correspondence. That is,a plurality of drive electrodes, which are arranged to be adjacent toeach other, may correspond to the unit drive circuit. FIG. 13illustrates an example where six drive electrodes correspond to the unitdrive circuit. That is, six drive electrodes TL(n)−1 to TL(n)−6, whichare arranged to be proximate and adjacent to each other, are regarded asone drive electrode TL(n) and correspond to the unit drive circuitsUSR(n) and USL(n).

When the unit drive circuits USR(n) and USL(n) form the selection signalwhich designates the corresponding drive electrode TL(n) in the electricfield touch detection, one end portion of each of the designated driveelectrode TL(n), that is, the six drive electrodes TL(n)−1 to TL(n)−6 isconnected to the signal wiring TSV on the side 2-L (FIGS. 8 and 9) side.In addition, the other end portion of each of the designated driveelectrode TL(n), that is, the six drive electrodes TL(n)−1 to TL(n)−6 isconnected to the signal wiring TSV on the side 2-R (FIGS. 8 and 9) side.Since the drive signal TSVCOM with the periodically changing voltage issupplied to the signal wiring TSV at the time of electric field touchdetection, the drive signal TSVCOM is supplied as the electric fielddrive signal to both the ends of the drive electrode TL(n), that is, thesix drive electrodes TL(n)−1 to TL(n)−6. As a result, the electric fieldis generated according to the electric field drive signal (the drivesignal TSVCOM).

On the other hand, when the unit drive circuits USR(n) and USL(n) formthe selection signal which designates the corresponding drive electrodeTL(n) in the magnetic field generation period TGT for the magnetic fieldtouch detection, the designated drive electrode TL(n), that is, thedrive electrodes TL(n−1) and TL(n+1) arranged to sandwich the six driveelectrodes TL(n)−1 to TL(n)−6 are connected to the signal wiring TSV andthe voltage wiring VCOM. The drive electrode TL(n−1) is configured bysix drive electrodes TL(n−1)−1 to TL(n−1)−6, and the drive electrodeTL(n+1) is also configured by six drive electrodes TL(n+1)−1 toTL(n+1)−6. FIG. 13 illustrates only the drive electrodes TL(n−1)−5,TL(n−1)−6, TL(n+1)−1 and TL(n+1)−2 among these drive electrodes, anddoes not illustrate the remaining drive electrodes TL(n−1)−1 toTL(n−1)−4 and TL(n+1)−3 to TL(n+1)−6.

When the description is given by exemplifying the drive electrodesTL(n−1)−5, TL(n−1)−6, TL(n+1)−1 and TL(n+1)−2 illustrated in FIG. 13,one end portion of each of the drive electrodes TL(n−1)−5 and TL(n−1)−6is connected to the signal wiring TSV on the side 2-L side. In addition,one end portion of each of the drive electrodes TL(n+1)−1 and TL(n+1)−2is connected to the voltage wiring VCOM on the side 2-L side. At thistime, the other end portion of each of the drive electrodes TL(n−1)−5and TL(n−1)−6 is connected to the voltage wiring VCOM on the side 2-Rside, and the other end portion of each of the drive electrodesTL(n+1)−1 and TL(n+1)−2 is connected to the signal wiring TSV on theside 2-R side. Similarly, one end portion of each of the driveelectrodes TL(n−1)−1 to TL(n−1)−4 (not illustrated) is also connected tothe signal wiring TSV on the side 2-L side, and the other end portionthereof is connected to the voltage wiring VCOM on the side 2-R side. Inaddition, one end portion of each of the drive electrodes TL(n+1)−3 toTL(n+1)−6 (not illustrated) is connected to the voltage wiring VCOM onthe side 2-L side, and the other end portion thereof is connected to thesignal wiring TSV on the side 2-R side.

In the magnetic field generation period TGT for the magnetic field touchdetection, the drive signal TSVCOM with the periodically changingvoltage is supplied to the signal wiring TSV, and the ground voltage Vssis supplied to the voltage wiring VCOM. Thus, a current indicated by thearrow I1 flows in the drive electrode TL(n−1) out of the driveelectrodes TL(n−1) and TL(n+1) arranged with the designated driveelectrode TL(n) sandwiched therebetween, and a current I2 in an oppositedirection to the current I1 flows in the drive electrode TL(n+1) asindicated by the arrow, as illustrated in FIG. 13. That is, the currentsin the directions opposite to each other flow, respectively, in thedrive electrodes TL(n−1) and TL(n+1) that are arranged with thedesignated drive electrode TL(n) sandwiched therebetween, according tothe voltage change of the magnetic field drive signal (the drive signalTSVCOM). Accordingly, the magnetic field generated around the driveelectrode TL(n−1) and the magnetic field generated around the driveelectrode TL(n+1) are superimposed on each other in the area where thedrive electrode TL(n) is arranged, thereby generating a strong magneticfield.

In addition, the six drive electrodes TL(n−1)−1 to TL(n−1)−6 areprovided as a bundle to form the drive electrode TL(n−1) so that themagnetic field generated around the drive electrode TL(n−1) becomesstrong in the example illustrated in FIG. 13. Similarly, the six driveelectrodes TL(n+1)−1 to TL(n+1)−6 are provided as a bundle to form thedrive electrode TL(n+1) so that the magnetic field generated around thedrive electrode TL(n+1) becomes strong. As a result, it is possible tofurther strengthen the superimposed magnetic field.

In this manner, it is possible to generate the strong magnetic fieldwithout forming the coil by connecting in series the drive electrodeTL(n−1) and the drive electrode TL(n+1) which are arranged to beparallel to each other. As a result, the control becomes easy, and it isfurther possible to suppress the increase of the area occupied by thecontrol circuit.

<<Configuration of Selection Drive Circuit>>

FIG. 14 is a block diagram illustrating each configuration of theselection drive circuits SSL and SSR according to the first embodiment.The selection drive circuit SSL and the selection drive circuit SSR havethe configurations similar to each other. First, the configuration ofthe selection drive circuit SSL will be described, and the selectiondrive circuit SSR will be described by mainly focusing on a differentpoint from the selection drive circuit SSL.

The selection drive circuit SSL is provided with the drive circuit SL-Rand the selection circuit SL-C as illustrated in FIG. 8. The drivecircuit SL-R includes the plurality of unit drive circuits USL(0) toUSL(p) which correspond, respectively, to the drive electrodes TL(0) toTL(p), and the selection circuit SL-C includes: a plurality of thirdswitches and fourth switches corresponding to each of the driveelectrodes TL(0) to TL(p); and the switch control circuit SWL. FIG. 14illustrates the drive electrodes TL(n) to TL(n+5) among the driveelectrodes TL(0) to TL(p), and a part of the selection drive circuit SSLwhich corresponds to these drive electrodes TL(n) to TL(n+5).Hereinafter, the selection drive circuit SSL will be described byexemplifying the part thereof which corresponds to the drive electrodesTL(n) to TL(n+5).

In FIG. 14, numerals USL(n) to USL(n+5) represent the unit drivecircuits which correspond to the drive electrodes TL(n) to TL(n+5). Eachof the unit drive circuits USL(n) to USL(n+5) has the shift stage. Therespective shift stages of the unit drive circuits USL(n) to USL(n+5)are connected in series, thereby forming the shift register. Theselection information SEI is supplied to the unit drive circuit USL(n)from the unit drive circuit USL (not illustrated) at the previous stageof the unit drive circuit USL(n) in the magnetic field generation periodTGT and the electric field touch detection period. The selectioninformation SEI is shifted in the shift register, which is configured bythe shift stages of the unit drive circuits USL(n) to USL(n+5), insynchronization with the clock signal CLK, and is shifted from the unitdrive circuit USL(n) toward the unit drive circuit USL(n+5). Inaddition, when the selection information SEI is shifted, the selectionsignal is outputted to the switch control circuit SWL from each of theunit drive circuits USL(n) to USL(n+5).

The switch control circuit SWL receives: the selection signals from theunit drive circuits USL(n) to USL(n+5); the magnetic field enable signalSC_EN; and the electric field enable signal TC_EN, and forms a firstdrive signal which performs switch control of third switches STLn toSTLn+5 and a second drive signal which performs switch control of fourthswitches SVLn to SVLn+5.

Each of the third switches STLn to STLn+5 and the fourth switches SVLnto SVLn+5 corresponds to each of the drive electrodes TL(n) to TL(n+5).For example, the third switch STLn and the fourth switch SVLn correspondto the drive electrode TL(n), and the third switch STLn+5 and the fourthswitch SVLn+5 correspond to the drive electrode TL(n+5). Each of theremaining third switch and fourth switch also corresponds to the driveelectrode one to one in the same manner.

Each of the third switches STLn to STLn+5 is connected between thesignal wiring TSV and one end portion of each of the corresponding driveelectrodes TL(n) to TL(n+5) on the side 2-L side of the display panel 2,and is subjected to the switch control according to the first drivesignal. Further, each of the fourth switches SVLn to SVLn+5 is connectedbetween the voltage wiring VCOM and one end portion of each of thecorresponding drive electrodes TL(n) to TL(n+5) on the side 2-L side ofthe display panel 2, and is subjected to the switch control according tothe second drive signal. When the description is given by exemplifyingthe third switches STLn and STLn+5 and the fourth switches SVLn andSVLn+5, the third switch STLn is connected between the signal wiring TSVand the one end portion of the drive electrode TL(n) on the side 2-Lside, and the fourth switch SVLn is connected between the voltage wiringVCOM and the one end portion of the drive electrode TL(n) on the side2-L side. In addition, the third switch STLn+5 is connected between thesignal wiring TSV and the one end portion of the drive electrode TL(n+5)on the side 2-L side, and the fourth switch SVLn+5 is connected betweenthe voltage wiring VCOM and one end portion of the drive electrodeTL(n+5) on the side 2-L side. The remaining third switch and fourthswitch are also configured in the same manner.

In the first embodiment, the selection circuit SL-C illustrated in FIG.8 is configured using the third switches STLn to STLn+5, the fourthswitches SVLn to SVLn+5, and the switch control circuit SWL.

In the selection drive circuit SSR, numerals USR(n) to USR(n+5) are unitdrive circuits which correspond to the above-described unit drivecircuits USL(n) to USL(n+5), and numeral SWR is a switch control circuitwhich corresponds to the above-described switch control circuit SWL. Inaddition, numerals STRn to STRn+5 are fifth switches which correspond tothe above-described third switches STLn to STLn+5, and numerals SVRn toSVRn+5 are sixth switches which correspond to the above-described fourthswitches SVLn to SVLn+5.

The shift stages in the unit drive circuits USR(n) to USR(n+5) areconnected in series, and the selection information SEI is shifted fromthe unit drive circuit USR(n) to USR(n+5) in synchronization with theclock signal CLK. At the time of being shifted, the selectioninformation SEI stored in the unit drive circuits USR(n) to USR(n+5) isoutputted to the switch control circuit SWR as the selection signals ofthe unit drive circuits USR(n) to USR(n+5). The switch control circuitSWR receives: the selection signal from the unit drive circuits USR(n)to USR(n+5); the magnetic field enable signal SC_EN; and the electricfield enable signal TC_EN, and forms a third drive signal which performsswitch control of the fifth switches STRn to STRn+5 and a fourth drivesignal which performs switch control of the sixth switches SVLn toSVLn+5.

The drive circuit SR-R configured using the unit drive circuits USR(n)to USR(n+5) and the selection circuit SR-C configured using the fifthswitch, the sixth switch, and the switch control circuit SWR arearranged along the side 2-R of the display panel 2 as illustrated inFIG. 8. Thus, each of the fifth switches STRn to STRn+5 is connectedbetween the signal wiring TSV and the other end portion of each of thecorresponding drive electrodes TL(n) to TL(n+5) on the side 2-R side. Inaddition, each of the sixth switches SVRn to SVRn+5 is connected betweenthe voltage wiring VCOM and the other end portion of each of thecorresponding drive electrodes TL(n) to TL(n+5) on the side 2-R side.

When the description is given by exemplifying the fifth switches STRnand STRn+5 and the sixth switches SVRn and SVRn+5, the fifth switch STRnis connected between the signal wiring TSV and the other end portion ofthe drive electrode TL(n) on the side 2-R side, and the sixth switchSVRn is connected between the voltage wiring VCOM and the other endportion of the drive electrode TL(n) on the side 2-R side. In addition,the fifth switch STRn+5 is connected between the signal wiring TSV andthe other end portion of the drive electrode TL(n+5) on the side 2-Rside, and the sixth switch SVRn+5 is connected between the voltagewiring VCOM and the other end portion of the drive electrode TL(n+5) onthe side 2-R side. The remaining fifth switch and sixth switch are alsoconfigured in the same manner.

The periodically changing drive signal TSVCOM is supplied to the signalwiring TSV at the time of the magnetic field touch detection in themagnetic field generation period TGT. In addition, the ground voltageVss is supplied to the voltage wiring VCOM at this time. FIGS. 15A to15C are waveform diagrams illustrating a waveform of each voltagesupplied to the signal wiring TSV and the voltage wiring VCOM in themagnetic field generation period TGT. In FIGS. 15A to 15C, thehorizontal axis represents time t, and the vertical axis represents avoltage. FIG. 15A illustrates a waveform of the drive signal TSVCOMsupplied to the signal wiring TSV arranged in the selection circuitSL-C, and FIG. 15B illustrates a waveform of the drive signal TSVCOMsupplied to the signal wiring TSV arranged in the selection circuitSR-C. In addition, FIG. 15C illustrates a voltage waveform of thevoltage wiring VCOM arranged in the selection circuits SL-C and SR-C.

As illustrated in FIGS. 15A to 15C, the drive signal TSVCOM supplied tothe selection circuit SL-C and the drive signal TSVCOM supplied to theselection circuit SR-C are synchronized with each other, and eachvoltage value periodically changes between the ground voltage Vss and apredetermined voltage (first voltage) Vp. On the other hand, the groundvoltage Vss is supplied to the voltage wiring VCOM.

The drive signals synchronized with each other are also supplied to thesignal wiring TSV arranged in the selection circuit SL-C and the signalwiring TSV arranged in the selection circuit SR-C at the time ofelectric field touch detection as illustrated in FIGS. 15A and 15B.Although not particularly limited, the predetermined voltage Vp of thedrive signal TSVCOM is different between the magnetic field generationperiod TGT and the time of electric field touch detection. In addition,a period of the drive signal TSVCOM illustrated in FIGS. 15A and 15B isalso different between the magnetic field generation period TGT and theelectric field touch detection period. Of course, the predeterminedvoltage Vp and the period may be the same therebetween without beinglimited thereto.

The switch control circuits SWL and SWR operate differently between acase where the magnetic field touch detection is designated by themagnetic field enable signal SC_EN and a case where the electric fieldtouch detection is designated by the electric field enable signal TC_EN.The operation in the case where the magnetic field touch detection isdesignated will be described with reference to FIGS. 16 and 17, and theoperation in the case where the electric field touch detection isdesignated will be described with reference to FIG. 18.

<<Operation of Magnetic Field Generation>>

FIGS. 16 and 17 are schematic plan views illustrating the operation inthe case where the magnetic field touch detection is designated.

When the selection signal supplied from the unit drive circuit indicatesselection, the switch control circuit SWL controls the third switch andthe fourth switch so that two drive electrodes arranged to sandwich thedrive electrode corresponding to the unit drive circuit which outputsthe selection signal indicating the selection are connected to thesignal wiring TSV and the voltage wiring VCOM. Although not particularlylimited, the switch control circuit SWL controls the third switch toconnect the drive electrode, which is closer to the side 2-U out of thetwo drive electrodes, to the signal wiring TSV, and the switch controlcircuit SWL controls the fourth switch to connect the drive electrode,which is closer to the side 2-D, to the voltage wiring VCOM in the firstembodiment.

Similarly, the switch control circuit SWR also controls the sixth switchand the fifth switch when the selection signal supplied from the unitdrive circuit indicates selection so that two drive electrodes arrangedto sandwich the drive electrode corresponding to the unit drive circuitwhich outputs the selection signal indicating the selection areconnected to the voltage wiring VCOM and the signal wiring TSV. In thefirst embodiment, the switch control circuit SWR controls the sixthswitch to connect the drive electrode, which is closer to the side 2-Uout of the two drive electrodes, to the voltage wiring VCOM, and theswitch control circuit SWL controls the fifth switch to connect thedrive electrode, which is closer to the side 2-D, to the signal wiringTSV.

The shift register configured using the unit drive circuits USL(n) toUSL(n+5) and the shift register configured using the unit drive circuitsUSR(n) to USR(n+5) operate in synchronization with each other. Thus, thedrive electrode whose one end portion is connected to the signal wiringTSV by the switch control circuit SWL has the other end portion which isconnected to the voltage wiring VCOM by the switch control circuit SWR.In addition, the drive electrode whose other end portion is connected tothe signal wiring TSV by the switch control circuit SWR has one endportion which is connected to the voltage wiring VCOM by the switchcontrol circuit SWL.

FIG. 16 illustrates a state where the unit drive circuit USL(n+2) andthe unit drive circuit USR(n+2) output the selection signal indicatingthe selection. The drive electrode corresponding to the unit drivecircuits USL(n+2) and USR(n+2) is the drive electrode TL(n+2), and thustwo drive electrodes arranged to sandwich the drive electrode TL(n+2)are the drive electrode TL(n+1) and the drive electrode TL(n+3). Theswitch control circuit SWL turns the third switch STLn+1 into theon-state by the first drive signal so that one end portion of the driveelectrode TL(n+1) arranged to be closer to the side 2-U out of the twodrive electrodes is connected to the signal wiring TSV. At this time,the switch control circuit SWL turns the fourth switch SVLn+3 into theon-state by the second drive signal so that one end portion of the driveelectrode TL(n+3) arranged to be closer to the side 2-D is connected tothe voltage wiring VCOM.

In addition, the switch control circuit SWL performs control using thefirst drive signal so that the remaining third switches STLn and STLn+2to STLn+5, except for the third switch STLn+1, are turned into theoff-state. Similarly, the switch control circuit SWL performs controlusing the second drive signal so that the remaining fourth switches SVLnto SVLn+2, SVLn+4 to SVLn+5, except for the fourth switch SVLn+3, areturned into the off-state.

On the other hand, the switch control circuit SWR turns the sixth switchSVRn+1 into the on-state by the fourth drive signal so that the otherend portion of the drive electrode TL(n+1) arranged to be closer to theside 2-U out of the two drive electrodes is connected to the voltagewiring VCOM. At this time, the switch control circuit SWR turns thefifth switch STRn+3 into the on-state by the third drive signal so thatthe other end portion of the drive electrode TL(n+3) arranged to becloser to the side 2-D is connected to the signal wiring TSV.

In addition, the switch control circuit SWR performs control using thethird drive signal so that the remaining fifth switches STRn to STRn+2,STRn+4 to STLn+5, except for the fifth switch STRn+3, are turned intothe off-state at this time. Similarly, the switch control circuit SWRperforms control using the fourth drive signal so that the remainingsixth switches SVLn, SVRn+2 to SVRn+5, except for the sixth switchSVRn+1, are turned into the off-state.

Accordingly, the drive electrode TL(n+1) out of the two drive electrodesarranged to sandwich the drive electrode TL(n+2) has the one end portionconnected to the signal wiring TSV and the other end portion connectedto the voltage wiring VCOM. At this time, the other drive electrodeTL(n+3) has the one end portion connected to the voltage wiring VCOM andthe other end portion connected to the signal wiring TSV. As illustratedin FIGS. 15A to 15C, when the drive signal TSVCOM whose voltage valueperiodically changes is supplied to the signal wiring TSV and the groundvoltage Vss is supplied to the voltage wiring VCOM, the current I1indicated by arrow in FIG. 16 flows in the drive electrode TL(n+1), andthe current I2 indicated by the arrow flows in the drive electrodeTL(n+3).

When the current I1 flows, the magnetic field ϕI1 indicated by thebroken-line arrow is generated around the drive electrode TL(n+1).Meanwhile, the current I2 in the opposite direction to the current I1flows in the drive electrode TL(n+3), and accordingly the magnetic fieldϕI2 indicated by the broken-line arrow is generated around the driveelectrode TL(n+3). Since the drive electrode TL(n+2) is sandwichedbetween the drive electrodes TL(n+1) and TL(n+3), the magnetic field ϕI1and the magnetic field ϕI2 are superimposed on each other in an area ofthe drive electrode TL(n+2), thereby generating a strong magnetic field.In addition, each of the drive electrodes TL(n), TL(n+2), TL(n+4) andTL(n+5), except for the drive electrodes TL(n+1) and TL(n+3), are in thefloating state at this time.

The selection information SEI indicating the selection is shifted fromthe unit drive circuits USL(n+2) and USR(n+2) to the unit drive circuitsUSL(n+3) and USR(n+3) as a clock signal CLK changes. Through such shift,the area where the strong magnetic field is generated is changed from anarea of the drive electrode TL(n+2) to an area of the drive electrodeTL(n+3). FIG. 17 illustrates a state where the strong magnetic field isgenerated around the drive electrode TL(n+3).

As the clock signal CLK changes, the selection information SEIindicating the selection is shifted to the unit drive circuits USL(n+3)and USR(n+3). The drive electrode corresponding to the unit drivecircuits USL(n+3) and USR(n+3) is the drive electrode TL(n+3). Thus, theswitch control circuits SWL and SWR connect the drive electrode TL(n+2),which is arranged to be more proximate to the side 2-U than the driveelectrode TL(n+3), to the signal wiring TSV and the voltage wiring VCOM.In addition, the switch control circuits SWL and SWR connect the driveelectrode TL(n+4), which is arranged to be more proximate to the side2-D than the drive electrode TL(n+3), to the voltage wiring VCOM and thesignal wiring TSV at this time. That is, the switch control circuit SWLturns the third switch STLn+2 into the on-state using the first drivesignal; the fourth switch SVLn+4 into the on-state using the seconddrive signal; and the remaining third switch and fourth switch into theoff-state. In addition, the switch control circuit SWR turns the fifthswitch SVRn+2 into the on-state using the third drive signal; the sixthswitch STRn+4 into the on-state using the fourth drive signal; and theremaining fifth switch and sixth switch into the off-state.

As a result, one end portion of the drive electrode TL(n+2) is connectedto the signal wiring TSV via the third switch STLn+2, and the other endportion thereof is connected to the voltage wiring VCOM via the fifthswitch SVRn+2. At this time, one end portion of the drive electrodeTL(n+4) is connected to the voltage wiring VCOM via the fourth switchSVLn+4, and the other end portion thereof is connected to the signalwiring TSV via the sixth switch SVRn+2. When the drive signal TSVCOM issupplied to the signal wiring TSV and the ground voltage Vss is suppliedto the voltage wiring VCOM, the current I1 indicated by arrow in FIG. 17flows in the drive electrode TL(n+2), and the current I2 indicated bythe arrow flows in the drive electrode TL(n+4).

When the currents I1 and I2 flow, the magnetic field ϕI1 indicated bythe broken-line arrow is generated around the drive electrode TL(n+2),and the magnetic field ϕI2 indicated by the broken-line arrow isgenerated around the drive electrode TL(n+4). The magnetic field φI1 andthe magnetic field φI2 are superimposed on each other in the area of thedrive electrode TL(n+3), thereby generating the strong magnetic field.In addition, each of the drive electrodes TL(n), TL(n+1), TL(n+3) andTL(n+5), except for the drive electrodes TL(n+2) and TL(n+4), is in thefloating state at this time.

As described above, it is possible to sequentially generate the magneticfield from the side 2-U to the side 2-D as the selection information SEIindicating the selection is shifted from the unit drive circuits USL(n)and USR(n) to the unit drive circuit USL(n+5), USR(n+5). In this case,it is possible to generate the strong magnetic field, without formingthe magnetic field generation coil, by connecting the drive electrodeswith each other.

<<Operation of Electric Field Generation>>

In a case where the electric field touch detection is instructed by theelectric field enable signal TC_EN, the switch control circuits SWL andSWR control the third switch and the fifth switch when the selectionsignal supplied from the unit drive circuit indicates selection so thatthe drive electrode corresponding to the unit drive circuit whichoutputs the selection signal indicating the selection is connected tothe signal wiring TSV. In order to generate an electric field, it isunnecessary to cause a DC current to flow in the drive electrodedifferently from the time of magnetic field generation, and thus theswitch control circuits SWL and SWR turn the fourth switch and the sixthswitch into the off-state.

FIG. 18 is a schematic plan view illustrating the operation in the casewhere the electric field touch detection is designated. FIG. 18illustrates a state where the unit drive circuits USL(n+2) and USR(n+2)output the selection signal indicating the selection.

When the selection signal indicating the selection is supplied from theunit drive circuit USL(n+2), the switch control circuit SWL turns thethird switch STLn+2, which is connected between one end portion of thedrive electrode TL(n+2) corresponding to the unit drive circuit USL(n+2)and the signal wiring TSV, into the on-state using the first drivesignal. In addition, the switch control circuit SWL performs controlusing the first drive signal so that the other third switches STLn toSTLn+1 and STLn+3 to STLn+5, except for the third switch STLn+2, areturned into the off-state at this time.

When the selection signal indicating the selection is supplied from theunit drive circuit USR(n+2), the switch control circuit SWR turns thefifth switch STRn+2, which is connected between the other end portion ofthe drive electrode TL(n+2) corresponding to the unit drive circuitUSR(n+2) and the signal wiring TSV, into the on-state using the thirddrive signal. In addition, the switch control circuit SWR performscontrol using the third drive signal so that the other fifth switchesSTRn to STRn+1 and STRn+3 to STRn+5, except for the fifth switch STRn+2,are turned into the off-state at this time.

The switch control circuits SWL and SWR turn the fourth switch and thesixth switch, except for the fourth switch SVLn+2 and the sixth switchSVRn+2 connected to the drive electrode TL(n+2) that generates theelectric field, into the on-state using the second drive signal and thefourth drive signal.

The drive signal TSVCOM with the periodically changing voltage issupplied to the signal wiring TSV even at the time of the electric fieldtouch detection. Thus, the drive signal TSVCOM is supplied to the oneend portion of the drive electrode TL(n+2) via the third switch STLn+2,and the drive signal TSVCOM is supplied to the other end portion of thedrive electrode TL(n+2) via the fifth switch STRn+2. As a result, thedrive signal TSVCOM is supplied to the drive electrode TL(n+2) from boththe end portions thereof, and accordingly the electric field accordingto the drive signal TSVCOM is generated around the drive electrodeTL(n+2).

The selection information SEI indicating the selection is shifted fromthe unit drive circuits USL(n+2) and USR(n+2) to the unit drive circuitsUSL(n+3) and USR(n+3) as a clock signal CLK changes. Accordingly, theswitch control circuit SWL turns the third switch STLn+3 into theon-state, and the switch control circuit SWR turns the fifth switchSTRn+3 into the on-state. At this time, the third switch except for thethird switch STLn+3 and the fifth switch except for the fifth switchSTRn+3 are turned into the off-state. Accordingly, the electric fieldaccording to the drive signal TSVCOM is generated around the driveelectrode TL(n+3) arranged next to the drive electrode TL(n+2).

In the above-described manner, the electric field is sequentiallygenerated from the drive electrode arranged on the side 2-U side to thedrive electrode arranged on the side 2-D side by changing the clocksignal CLK.

Although FIGS. 15A to 18 illustrate the example where each one of thethird switch, the fourth switch, the fifth switch, and the sixth switchis connected to one drive electrode, the invention is not limitedthereto. As illustrated in FIG. 13, for example, each one of the thirdswitch, the fourth switch, the fifth switch, and the sixth switch may beconnected to the six (plural) drive electrodes arranged to be adjacentto each other.

In addition, the third switch, the fourth switch, the fifth switch, andthe sixth switch, which are connected to each of the drive electrodesadjacent to each other, may be subjected to the switch controlsubstantially at the same time based on the selection information sentfrom the same unit drive circuit. In FIG. 16, for example, the thirdswitch STLn connected to the drive electrode TL(n) and the third switchSTLn+1 connected to the drive electrode TL(n+1) may be turned into theon-state substantially at the same time based on the selection signalsent from the unit drive circuit USL(n+2), and the sixth switch SVRnconnected to the drive electrode TL(n) and the sixth switch SVRn+1connected to the drive electrode TL(n+1) may be turned into the on-statesubstantially at the same time based on the selection signal sent fromthe unit drive circuit USR(n+2). Accordingly, it is possible to generatethe magnetic field by collectively using the drive electrode TL(n) andthe drive electrode TL(n+1) and to strengthen the magnetic field thusgenerated.

When the drive electrode TL(n) and the drive electrode TL(n+1) arecollectively used, it is possible to further strengthen the magneticfield generated in the area of the drive electrode TL(n+2) bycollectively using the drive electrode TL(n+3) and the drive electrodeTL(n+4) in the same manner. In this case, the configuration where thedrive electrode TL(n+3) and the drive electrode TL(n+4) are collectivelyused is the same as the configuration where the drive electrode TL(n)and the drive electrode TL(n+1) are collectively used.

For example, it is possible to reduce the number of switches in theconfiguration of the first embodiment as compared to the configurationillustrated in FIGS. 36 and 37. Thus, the control becomes easy, and itis possible to suppress the increase of the occupied area.

<Configuration of Switching Regulator Circuit>

FIG. 19 is a plan view illustrating the configuration of the displaydevice 1 according to the first embodiment. FIG. 19 illustrates a stateat the time of magnetic field touch detection. As described withreference to FIGS. 14 to 17, the magnetic field is generated using thedrive electrode in the magnetic field generation period TGT at the timeof magnetic field touch detection. As described with reference to FIGS.1 to 2B, the electric charge amount to be charged in the capacitiveelement C inside the pen is changed by the magnetic field generated inthe magnetic field generation period TGT depending on whether the pen isproximate. In the magnetic field detection period TDT, the magneticfield generated by the coil L1 inside the pen is detected based on theelectric charge amount stored in the capacitive element C inside thepen.

The description has been given in FIGS. 1 to 2B by exemplifying the casewhere the magnetic field generation coil and the magnetic fielddetection coil are configured using the same coil. On the contrary, themagnetic field is generated without using the coil (magnetic fieldgeneration coil) and the magnetic field from the pen is detected by themagnetic field detection coil in the magnetic field generation periodTGT in the first embodiment as described in FIGS. 14 to 17.

In the first embodiment, the magnetic field detection coil is formedusing the signal line in the magnetic field detection period TDT.

FIG. 19 does not illustrate the drive electrode used for the magneticfield generation in the magnetic field generation period TGT, butillustrates only the signal line forming the magnetic field detectioncoil in the magnetic field detection period TDT. The signal line is usedto detect the magnetic field in the magnetic field detection period TDT,and thus can be regarded as the detection electrode. When it is regardedin this manner, only the detection electrode can be regarded as beingdrawn in FIG. 19.

In FIG. 19, the coil L1 inside the pen generates the magnetic fieldbased on electric charges of the capacitive element C which is chargedby the voltage induced by the magnetic field in the magnetic fieldgeneration period TGT. In FIG. 19, numerals SL(0) to SL(p) represent thesignal lines. The signal lines SL(0) to SL(p) cross the drive electrodesTL(0) to TL(p) as illustrated in FIG. 10. That is, the signal linesSL(0) to SL(p) are arranged in parallel to each other between the side2-R and the side 2-L of the display panel 2.

Although not particularly limited, a signal line SL(dL) for magneticfield is arranged along the side 2-L of the display panel 2, and asignal line SL(dR) for magnetic field is arranged along the side 2-R ofthe display panel 2 in the first embodiment. That is, provided are themagnetic field signal line SL(dR) (second signal line) arranged to beparallel to the signal lines SL(0) to SL(p) (first signal line) alongthe side 2-R outside the active area of the display panel 2, and themagnetic field signal line SL(dL) (second signal line) arranged to beparallel to the signal lines SL(0) to SL(p) along the side 2-R outsidethe active area of the display panel 2. The magnetic field signal linesSL(dR) and SL(dL) are provided outside the active area of the displaypanel 2, and thus are used at the time of magnetic field touch detectionwithout affecting the display.

In the first embodiment, the switching regulator circuit SCX is arrangedalong the side 2-U of the display panel 2. In FIG. 19, the upper sideindicates the side 2-U of the display panel 2 side, and the lower sideindicates the side 2-D of the display panel 2 side. The switchingregulator circuit SCX is provided with seventh switches j00 and j01 andeighth switches k00 to kp.

The signal lines SL(0) to SL(p) are arranged from the side 2-L to theside 2-R of the display panel 2 in this order although not particularlylimited thereto. In the first embodiment, the signal lines, which arearranged with two signal lines sandwiched therebetween, are connected toeach other by the eighth switches k00 to kp in the magnetic fielddetection period TDT. When the description is given by exemplifying FIG.19, the eighth switch k00 is connected between an end portion of thesignal line SL(1) and an end portion of the signal line SL(4), and theeighth switch k01 is connected between an end portion of the signal lineSL(3) and an end portion of the signal line SL(6). In addition, theeighth switch kn−1 is connected between an end portion of the signalline SL(n−2) and an end portion of the signal line SL(n+1); the eighthswitch kn is connected between an end portion of the signal line SL(n)and an end portion of the signal line SL(n+3); and the eighth switchkn+1 is connected between an end portion of the signal line SL(n+2) andan end portion of the signal line SL(n+5).

Further, the eighth switch kp−1 is connected between an end portion ofthe signal line SL(p−6) and an end portion of the signal line SL(p−3),and the eighth switch kp is connected between an end portion of thesignal line SL(p−4) and an end portion of the signal line SL(p−1).

The seventh switch j00 is connected between an end portion of themagnetic field signal line SL(dL) and an end portion of the signal lineSL(2), and the seventh switch j01 is connected between an end portion ofthe magnetic field signal line SL(dR) and an end portion of the signalline SL(p−2).

Each of the seventh switches j00 and j01 and the eighth switches k00 tokp is subjected to the switch control by the magnetic field enablesignal SC_EN. In the first embodiment, the seventh switches j00 and j01and the eighth switches k00 to kp are turned into the on-state when themagnetic field enable signal SC_EN designates the magnetic field touchdetection, and turned into the off-state in the other cases.

As a result, the signal lines with the two signal lines sandwichedtherebetween are electrically connected to each other at the time ofmagnetic field touch detection. When the description is given byexemplifying FIG. 19, the signal lines SL(1) and SL(4), which arearranged with the signal lines SL(2) and SL(3) sandwiched therebetween,are electrically connected to each other via the eighth switch k00. Inthe same manner, the signal line SL(3) and the signal line SL(6), whichare arranged with the signal lines SL(4) and SL(5) sandwichedtherebetween, are connected to each other via the eighth switch k01; thesignal line SL(n−2) and the signal line SL(n+1), which are arranged withthe signal lines SL(n−1) and SL(n) sandwiched therebetween, areconnected to each other via the eighth switch kn−1; the signal lineSL(n) and the signal line SL(n+3), which are arranged with the signallines SL(n+1) and SL(n+2) sandwiched therebetween, are connected to eachother via the eighth switch kn; and the signal line SL(n+2) and thesignal line SL(n+5), which are arranged with the signal lines SL(n+3)and SL(n+4) sandwiched therebetween, are connected to each other via theeighth switch kn+1.

Further, the signal line SL(p−6) and the signal line SL(p−3), which arearranged with the signal lines SL(p−5) and SL(p−4) sandwichedtherebetween, are connected to each other via the eighth switch kp−1;and the signal line SL(p−4) and the signal line SL(p−2), which arearranged with the signal lines SL(p−3) and SL(p−2) sandwichedtherebetween, are connected to each other via the eighth switch kp.

Further, the magnetic field signal line SL(dL) and the signal lineSL(2), which are arranged with the signal lines SL(0) and SL(1)sandwiched therebetween, are connected to each other via the seventhswitch j00; and the magnetic field signal line SL(dR) and the signalline SL(p−2), which are arranged with the signal lines SL(p−1) and SL(p)sandwiched therebetween, are connected to each other via the seventhswitch j01 in the first embodiment.

Accordingly, the magnetic field detection coil is formed using aplurality of arbitrary signal lines among the signal lines SL(0) toSL(p) in the magnetic field detection period TDT. In the firstembodiment, it is also possible to form the magnetic field detectioncoil in the vicinity of the sides 2-R and 2-L of the display panel 2 inthe magnetic field detection period TDT. That is, it is possible to formthe magnetic field detection coil, which inside has the signal linesSL(0) and SL(1) arranged to be proximate to the side 2-L of the displaypanel 2, using the magnetic field signal line SL(dL) and the signal lineSL(2) as a winding. Similarly, it is possible to form the magnetic fielddetection coil, which inside has the signal lines SL(p−1) and SL(p)arranged to be proximate to the side 2-R of the display panel 2, usingthe magnetic field signal line SL(dR) and the signal line SL(p−2) as awinding. Accordingly, it is also possible to detect a case where the penis proximate to the vicinity of the side 2-R and the side 2-L. Inaddition, the magnetic field detection coils to be formed overlap eachother in the first embodiment as understood from FIG. 19. Accordingly,it is possible to prevent a miss in detection.

Widths d8 and d10 of the magnetic field signal lines SL(dR) and SL(dL)are narrower than widths d9 and d10 of the signal lines SL(0) to SL(p).Accordingly, it is possible to suppress the increase of the frame.

In the magnetic field detection period TDT, the ground voltage Vss issupplied to one terminal out of a pair of terminals of each of themagnetic field detection coils formed by the signal lines, and the otherterminal is connected to the amplifier circuit AMP described in FIG. 8.When the description is given by exemplifying FIG. 19, the end portionof each of the signal lines SL(n−2), SL(n) and SL(n+2) is connected tothe amplifier circuit AMP. When the magnetic field from the pen reachesthe magnetic field detection coil configured by the signal lines, theinduced voltage is generated in the magnetic field detection coil, andan input signal of the amplifier circuit AMP is changed. The amplifiercircuit AMP amplifies this change of the input signal, and outputs theamplified signal as the sense signals S(0) to S(p).

Meanwhile, the seventh switches j00 and j01 and the eighth switches k00to kp are turned into the off-state at the time of electric field touchdetection. At the time of electric field touch detection, the driveelectrode generates the electric field as described with reference toFIGS. 14 and 18. The electric field around the signal line is changeddepending on whether the finger is touched, and this change is sent tothe amplifier circuit AMP, and amplified and outputted as the sensesignals S(0) to S(p).

The first embodiment has shown the example where the magnetic fieldsignal lines SL(dR) and SL(dL), which serve as the winding at the timeof forming the magnetic field detection coil, are provided along theboth sides of the display panel 2, but the magnetic field signal linesSL(dR) and SL(dL) may be provided on any one side, of course.

FIG. 20 is a perspective view schematically illustrating theconfiguration of the display device 1 according to the first embodiment.FIG. 20 illustrates the drive electrodes TL(0) to TL(p), the signallines SL(0) to SL(p), the eighth switches k00 to kp, the drivesemiconductor device DDIC, the selection drive circuits SSR and SSL, andthe gate driver 5. These parts are formed on the TFT glass substrateTGB. Thus, FIG. 20 can be also regarded as illustrating the displaydevice 1 mounted to the module. In addition, FIG. 20 also illustratesthe pen provided with the coil L1.

The selection drive circuit SSR is arranged along the side 900-R of themodule, and the selection drive circuit SSL and the gate driver 5 arearranged along the side 900-L. The signal lines SL(0) to SL(p) arearranged to be parallel to each other between the selection drivecircuit SSL and the selection drive circuit SSR, and the eighth switchesk00 to kp are arranged along the side 900-U of the module. The driveelectrodes TL(0) to TL(p) are orthogonal to the signal lines SL(0) toSL(p), and arranged to be parallel to each other.

The eighth switches k00 to kp connect the signal lines to each otherduring the touch detection as described with reference to FIG. 19. InFIG. 20, ninth switches l00 to lp formed on the TFT glass substrate TGBare arranged along the side 900-D of the module.

The ninth switches l00 to lp are divided into two groups, the ninthswitches of a first group being connected between an end portion of eachof the signal lines, to which the ground voltage Vss needs to besupplied in the magnetic field detection period TDT, for example, thesignal lines SL(2), SL(n+3), SL(p−1) etc. illustrated in FIG. 19, and avoltage wiring VL3, and being turned into the on-state in the magneticfield detection period TDT. In addition, the ninth switches of a secondgroup are connected between an end portion of the signal line, whichoutputs the change of the signal in the coil in the magnetic fielddetection period TDT, for example, the signal lines SL(1), SL(n),SL(p−4) etc. illustrated in FIG. 19, and a corresponding signal wiringLL7. In FIG. 20, reference signs l00, ln, ln+3 and lp are attached, forexample, to the ninth switch (second group) connected to the end portionof the signal line SL(0); the ninth switch (second group) connected tothe end portion of the signal line SL(n); the ninth switch (first group)connected to the end portion of the signal line SL(n+3); and the ninthswitch (first group) connected to the end portion of the signal lineL(p), respectively. The number of signal wirings included in the signalwiring LL7 corresponds to the number of the ninth switches of the secondgroup although illustrated as a single wiring. The ninth switches of thesecond group are also turned into the on-state in the magnetic fielddetection period. Accordingly, the signal generated in each of the coilsis transmitted to the corresponding signal wiring LL7, amplified by theamplifier circuit AMP, and supplied to the touch detection semiconductordevice 6 (FIG. 8) as the sense signals S(0) to S(p).

The ninth switches of the second group is also turned into the on-state,the signal change in the signal line is supplied to the amplifiercircuit AMP, amplified, and supplied to the touch detectionsemiconductor device 6 (FIG. 8) as the sense signals S(0) to S(p) at thetime of electric field touch detection.

In the first embodiment, the ninth switches l00 to lp are formed on theTFT glass substrate, and the drive semiconductor device DDIC is arrangedto cover the ninth switches l00 to lp. Accordingly, it is possible tosuppress widening of the frame.

Although not particularly limited, the signal wiring TSV and the voltagewiring VCOM extend along the side 900-R and 900-L of the module. Thedrive signal TSVCOM is supplied to the signal wiring TSV, and the groundvoltage Vss is supplied to the voltage wiring VCOM in the magnetic fieldgeneration period TGT. In addition, the drive signal TSVCOM is suppliedto the signal wiring TSV at the time of electric field touch detection.

The selection drive circuits SSL and SSR cause the current I1 in thedirection indicated by the arrow to flow in the drive electrodes TL(n−1)and TL(n) in the magnetic field generation period TGT for the magneticfield touch detection. In addition, the selection drive circuits SSL andSSR cause the current I2 in the direction indicated by the arrow to flowin the drive electrodes TL(n+3) and TL(n+4) at this time. Accordingly,the drive signal TSVCOM periodically changes, and so the periodicallychanging magnetic field is generated around each of the drive electrodesTL(n−1), TL(n), TL(n+3) and TL(n+4). In FIG. 20, each state of thegenerated magnetic fields ϕI1 and ϕI2 is schematically illustrated inthe broken line. The magnetic fields ϕI1 and ϕI2 are superimposed oneach other in an area of the drive electrodes TL(n−1) and TL(n+1)sandwiched among the drive electrodes TL(n−1), TL(n), TL(n+3) andTL(n+4), thereby generating a strong magnetic field.

When the pen is present in the vicinity of the area where the strongmagnetic field is generated, the coil L1 inside the pen generates theinduced voltage due to the action of mutual induction. The capacitiveelement C (not illustrated) inside the pen PN is charged by thegenerated induced voltage.

The coil L1 inside the pen generates the magnetic field by the electriccharges charged in the capacitive element C in the magnetic fielddetection period TDT. Magnetic lines at this time are represented by ϕDin FIG. 20.

As described with reference to FIG. 19, the eighth switches k00 to kpare turned into the on-state in the magnetic field detection period TDT.Accordingly, the plurality of coils are formed using the signal linesSL(0) to SL(p) as each winding. The induced voltage is generated in thecoil using the signal line as the winding due to the action of mutualinduction between the coil using the signal line as the winding and thepen-in coil L1, and the signal in the signal line is transmitted to theninth switches of the second group. When the ninth switches of thesecond group are turned into the on-state, the signal is outputted fromthe amplifier circuit AMP as the sense signals S(0) to S(p). In FIG. 20,the signal transmitted to the ninth switch ln via the signal line SL(n)is indicated by the solid line with the arrow. Accordingly, thecoordinate touched by the pen can be specified by specifying thedetection electrode which detects the magnetic field at the time ofdriving the drive electrode which has generated the magnetic field.

Although the description has been given regarding the example where themagnetic field signal lines SL(dL) and SL(dR) are arranged outside theactive area of the display panel 2, the invention is not limitedthereto. For example, the magnetic field signal line SL(dL) and/or themagnetic field signal line SL(dR) may be arranged along each of thesides 2-L and 2-R inside the active area of the display panel 2. In thiscase, it is possible to reduce narrowing of the display area by settingthe width d10 of the magnetic field signal wiring SL(dL) and/or SL(dR)to be arranged to be narrower than a width d11 of the signal line.

Modified Example

FIG. 21 is a perspective view schematically illustrating a configurationof the display device 1 according to a modified example of the firstembodiment. Since FIG. 21 is similar to FIG. 20, a different point fromFIG. 20 will be mainly described. In the display device 1 illustrated inFIG. 20, the magnetic field detection coil has been formed using thesignal lines SL(0) to SL(p) at the time of magnetic field touchdetection. In addition, the change in the electric field has been alsodetected using the signal lines SL(0) to SL(p) at the time of electricfield touch detection. In regard to this, detection electrodes RL(0) toRL(p) formed on the CF glass substrate CGB are used to form a magneticfield detection coil at the time of magnetic field touch detection inthe modified example. In addition, the detection electrodes RL(0) toRL(p) are also used to detect a change in an electric field at the timeof electric field touch detection. That is, the detection electrodesRL(0) to RL(p) formed on the CF glass substrate CGB are used at eachtime of magnetic field touch detection and electric field touchdetection instead of the signal lines SL(0) to SL(p) illustrated in FIG.20.

The detection electrodes RL(0) to RL(p) are formed on the main surfaceCSF1 of the CF glass substrate CGB as illustrated in FIGS. 4A and 4B.Thus, the detection electrodes RL(0) to RL(p) are formed on the driveelectrodes TL(0) to TL(p) with the liquid crystal layer, the colorfilter, and the CF glass substrate CGB sandwiched therebetween. Whenseen in a plan view from the main surface CSF1 of the CF glass substrateCGB side, the detection electrodes RL(0) to RL(p) are parallel to eachother and are arranged to orthogonal to the drive electrodes TL(0) toTL(p).

In FIG. 21, one end portions the detection electrodes RL(0) to RL(p) areconnected to each other with a predetermined interval. In the modifiedexample, the one end portions of the detection electrodes RL(0) to RL(p)are connected to each other with an interval that causes two detectionelectrodes to be sandwiched therebetween, similarly to the signal linesSL(0) to SL(p) illustrated in FIG. 20. This connection is achieved byconnecting the detection electrodes using the signal wiring formed onthe CF glass substrate CGB. In FIG. 21, reference signs are attachedonly to the detection electrodes RL(0) to RL(6), RL(n), RL(n+3) andRL(p−3) to RL(p) among the detection electrodes RL(0) to RL(p) in orderto facilitate the viewability of the drawing. When the description isgiven by exemplifying FIG. 21, the one end portions of the detectionelectrodes RL(1) and RL(4) are connected to each other on the side 900-Uof the module side. In addition, the one end portions of the detectionelectrode RL(3) and RL(6) are connected to each other. Incidentally, theone end portion of the detection electrode RL(2) is connected to the oneend portion of the detection electrode RL(0), which is the mostproximate to the side 900-L of the module with the single detectionelectrode TL(1) sandwiched therebetween. One end portions of the otherdetection electrodes are also connected to each other so as to sandwichtwo detection electrodes except for the detection electrode RL(p−3).

The respective other end portions of the detection electrodes RL(0) toRL(p) are connected to the ninth switches l00 to lp formed on the TFTglass substrate TGB. In FIG. 21, the ninth switches l00 to lp are drawnon the CF glass substrate CGB to illustrate each connection between thedetection electrodes RL(0) to RL(p) and the ninth switches l00 to lp,but the ninth switches l00 to lp are formed on the TFT glass substrateTGB similarly to FIG. 20. Further, the ninth switches l00 to lp arecovered by the drive semiconductor device DDIC, similarly to theillustration in FIG. 20. In FIG. 21, the drive semiconductor device DDICis indicated by the broken line on the TFT glass substrate TGB.

The ninth switches l00 to lp illustrated in FIG. 21 are configured by afirst group and a second group, similarly to the ninth switches l00 tolp illustrated in FIG. 20. In the magnetic field detection period TDT,the ground voltage Vss is supplied to an end portion of the magneticfield detection coil formed using the detection electrodes RL(0) toRL(p) as the ninth switches of the first group are turned into theon-state, and the end portion of the magnetic field detection coil isconnected to the amplifier circuit AMP as the ninth switches of thesecond group are turned into the on-state.

In the modified example, the magnetic field is also generated by thedrive electrodes TL(0) to TL(p) in the magnetic field generation periodTGT similarly to FIG. 20. When the pen generates the magnetic field ϕDbased on the generated magnetic field in the magnetic field detectionperiod TDT, the magnetic field ϕD is detected by the magnetic fielddetection coil formed using the detection electrodes RL(0) to RL(p) andoutputted from the amplifier circuit AMP as the sense signals S(0) toS(p). Thus, the coordinate touched by the pen can be specified byspecifying the detection electrode which is detected the magnetic fieldat the time of driving the drive electrode which is generated themagnetic field.

Similarly to FIG. 20, an electric field is generated by the driveelectrodes TL(0) to TL(p) at the time of electric field touch detection,and a change in the electric field caused depending on whether thefinger is touched is transmitted to the amplifier circuit AMP by thedetection electrodes RL(0) to RL(p) and is outputted as the sensesignals S(0) to S(p).

The signal lines SL(0) to SL(p) are used to transmit the imageinformation in the display period, and thus need to be electricallyisolated from each other in the display period. Thus, the seventh switchand the eighth switch are provided in the display device 1 illustratedin FIGS. 19 and 20. In regard to this, the magnetic field touchdetection and the electric field touch detection are performed using thedetection electrodes RL(0) to RL(p) without using the signal lines SL(0)to SL(p) in the modified example illustrated in FIG. 21. Thus, it isunnecessary to provide the seventh switch and the eighth switch for themagnetic field touch detection, and it is possible to suppress theincrease of the occupied area.

Since it is not required to form the magnetic field generation coil inthe first embodiment, the control becomes easy, and it is possible tosuppress the increase of the occupied area of the control circuit.

Second Embodiment

FIG. 22 is a plan view illustrating a configuration of the displaydevice 1 according to a second embodiment. FIG. 22 illustrates only apart relating to the display panel 2 described in the first embodiment,and does not illustrate the other parts.

In FIG. 22, numerals TL(0) to TL(p) represent drive electrodes arrangedin parallel to each other between the side 2-U and the side 2-D of thedisplay panel 2. In addition, numeral TL(dLU) represents a dummy driveelectrode for magnetic field generation, which is arranged along theside 2-U in an area (non-active area) outside the display panel 2, andnumeral TL(dLD) represents a dummy drive electrode for magnetic fieldgeneration which is arranged along the side 2-D in the area (non-activearea) outside the display panel 2. The dummy drive electrodes formagnetic field generation are arranged in the external area of thedisplay panel 2, and thus will be referred to also as an external areadrive electrode, hereinafter.

In addition, each of numerals USL(0) to USL(p) and USR(0) to USR(p)represents a unit drive circuit in FIG. 22. As described with referenceto FIGS. 14, 16 and 17, the respective unit drive circuits USL(0) toUSL(p) are arranged along the side 2-L of the display panel 2, andcorrespond to the drive electrodes TL(0) to TL(p). In addition, therespective unit drive circuits USR(0) to USR(p) are arranged along theside 2-R of the display panel 2, and correspond to the drive electrodesTL(0) to TL(p).

As described in the first embodiment, the drive signal TSVCOM issupplied to two drive electrodes, arranged to sandwich a drive electrodecorresponding to a unit drive circuit which outputs a selection signaldesignating selection, in the magnetic field generation period TGT. Forexample, when the unit drive circuits USL(2) and USR(2) output theselection signal designating selection in the magnetic field generationperiod TGT, the drive signal TSVCOM is supplied to the drive electrodesTL(1) and TL(3) which are arranged to sandwich the drive electrode TL(2)corresponding to the unit drive circuits USL(2) and USR(2). That is, thedrive signal TSVCOM is supplied to one end portion of the driveelectrode TL(1) from the side 2-L side, and the ground voltage Vss issupplied to the other end portion of the drive electrode TL(1) from theside 2-R side. At this time, the drive signal TSVCOM is supplied to theother end portion of the drive electrode TL(3) from the side 2-R side,and the ground voltage Vss is supplied to one end portion of the driveelectrode TL(3) from the side 2-L side. Accordingly, the magnetic fieldgenerated around the drive electrode TL(1) and the magnetic fieldgenerated around the drive electrode TL(3) are superimposed on eachother around the drive electrode TL(2) to be selected, therebygenerating a strong magnetic field.

In this case, a drive electrode proximate to the drive electrode TL(0)is only the drive electrode TL(1) when the drive electrode TL(0)arranged to be proximate to the side 2-U of the display panel 2 isselected. Thus, the magnetic field generated around the drive electrodeTL(0) becomes weak when the drive electrode TL(0) is selected.Similarly, a drive electrode proximate to the drive electrode TL(p) isonly the drive electrode TL(p−1) when the drive electrode TL(p) arrangedto be proximate to the side 2-D of the display panel 2 is selected.Thus, the magnetic field generated around the drive electrode TL(p)becomes weak when the drive electrode TL(p) is selected.

In the second embodiment, the external area drive electrode TL(dLU) isarranged at the opposite side to the drive electrode TL(0) with the side2-U sandwiched therebetween, and the external area drive electrodeTL(dLD) is arranged at the opposite side to the drive electrode TL(p)with the side 2-D sandwiched therebetween.

When the drive electrode TL(0) is caused to generate the magnetic field,each of the drive electrode TL(1) and the external area drive electrodeTL(dLU) arranged with the drive electrode TL(0) sandwiched therebetweenis caused to generate the magnetic field. In addition, when the driveelectrode TL(p) is caused to generate the magnetic field, each of thedrive electrode TL(p−1) and the external area drive electrode TL(dLD)arranged with the drive electrode TL(p) sandwiched therebetween iscaused to generate the magnetic field. Accordingly, it is possible toprevent reduction in accuracy of detection of the pen in an area closerto the sides 2-U and 2-D of the display panel 2.

Incidentally, the external area drive electrodes TL(dLU) and TL(dLD) areused only for the magnetic field generation, and thus each of linewidths dLU and dLD may be narrower than each line width dd of the driveelectrodes TL(0) to TL(p).

FIG. 23 is a plan view illustrating the case of generating the magneticfield around the drive electrode TL(0). The selection circuit SL-C(FIGS.8 and 14) is configured so that the drive signal TSVCOM is supplied toone end portion of the external area drive electrode TL(dLU) on the side2-L side in response to the selection signal from the unit drive circuitUSL(0), and that the ground voltage Vss is supplied to the one endportion of the drive electrode TL(1) on the side 2-L side when the unitdrive circuits USL(0) and USR(0) corresponding to the drive electrodeTL(0) output the selection signal indicating the selection in themagnetic field generation period TGT. In addition, the selection circuitSR-C(FIGS. 8 and 14) is configured so that the ground voltage Vss issupplied to the other end portion of the external area drive electrodeTL(dLU) on the side 2-R side in response to the selection signal fromthe unit drive circuit USR(0) at this time, and that the drive signalTSVCOM is supplied to the other end portion of the drive electrode TL(1)on the side 2-R side.

Accordingly, when the drive electrode TL(0) arranged to be the mostproximate to the side 2-U is selected, the current I2 with the arrowflows in the drive electrode TL(1), thereby generating the magneticfield. In addition, the current I1 with the arrow flows in the externalarea drive electrode TL(dLU), thereby generating the magnetic field. Themagnetic field generated by the drive electrode TL(1) and the magneticfield generated by the external area drive electrode TL(dLU) aresuperimposed on each other in an area of the drive electrode TL(0), andso it is possible to generate a strong magnetic field in the area of thedrive electrode TL(0).

FIG. 24 is a plan view illustrating the case of generating the magneticfield around the drive electrode TL(p). The selection circuit SL-C(FIGS.8 and 14) is configured so that the ground voltage Vss is supplied tothe one end portion of the external area drive electrode TL(dLU) on theside 2-L side in response to the selection signal from the unit drivecircuit USL(p), and that the drive signal TSVCOM is supplied to one endportion of the drive electrode TL(p−1) on the side 2-L side when theunit drive circuits USL(p) and USR(p) corresponding to the driveelectrode TL(p) output the selection signal indicating the selection inthe magnetic field generation period TGT. In addition, the selectioncircuit SR-C(FIGS. 8 and 14) is configured so that the drive signalTSVCOM is supplied to the other end portion of the external area driveelectrode TL(dLU) on the side 2-R side in response to the selectionsignal from the unit drive circuit USR(p) at this time, and that theground voltage Vss is supplied to the other end portion of the driveelectrode TL(p−1) on the side 2-R side.

Accordingly, when the drive electrode TL(p) arranged to be the mostproximate to the side 2-D is selected, the current I1 with the arrowflows in the drive electrode TL(p−1), thereby generating the magneticfield. In addition, the current I2 with the arrow flows in the externalarea drive electrode TL(dLD), thereby generating the magnetic field. Themagnetic field generated by the drive electrode TL(p−1) and the magneticfield generated by the external area drive electrode TL(dLD) aresuperimposed on each other in an area of the drive electrode TL(p), andso it is possible to generate a strong magnetic field in the area of thedrive electrode TL(p).

The description has been given regarding the example where the drivesignal TSVCOM and the ground voltage Vss are supplied to the two driveelectrodes, which are arranged to sandwich the drive electrodecorresponding to the unit drive circuit that outputs the selectionsignal indicating the selection, in the magnetic field generation periodTGT, but the invention is not limited thereto. For example, two driveelectrodes, which are arranged to sandwich a drive electrodecorresponding to an area where a strong magnetic field is generated, maybe selected by the corresponding unit selection circuit. In this case,the unit drive circuits USL(dU) and USR(dU) are arranged at both endportions of the external area drive electrode TL(dLU), and the unitdrive circuits USL(dD) and USR(dD) are arranged at both end portions ofthe external area drive electrode TL(dLD) as illustrated in FIGS. 22 to24.

In this case, among the unit drive circuits USL(0) to USL(p), USL(dL)and USL(dD), two unit drive circuits, which are arranged to sandwich theunit drive circuit corresponding to the drive electrode that generatesthe strong magnetic field, output the selection signal indicating theselection in the magnetic field generation period TGT. Similarly, amongthe unit drive circuits USR(0) to USR(p), USR(dL) and USR(dD), two unitdrive circuits, which are arranged to sandwich the unit drive circuitcorresponding to the drive electrode that generates the strong magneticfield, output the selection signal indicating the selection.

For example, when a strong magnetic field is caused to be generated inan area of the drive electrode TL(2), the unit drive circuit USL(1) andthe unit drive circuit USL(3) arranged to sandwich the unit selectioncircuit USL(2) output the selection signal indicating the selection. Theselection circuit SL-C(FIGS. 8 and 14) supplies the drive signal TSVCOMto the one end portion of the drive electrode TL(1) corresponding to theunit selection circuit USL(1) based on the selection signals from theunit selection circuits USL(1) and USL(3), and supplies the groundvoltage Vss to the one end portion of the drive electrode TL(3)corresponding to the unit selection circuit USL(3).

At this time, the unit drive circuit USR(1) and the unit drive circuitUSR(3), which are arranged to sandwich the unit selection circuit USR(2)corresponding to the drive electrode TL(2), output the selection signalindicating the selection. The selection circuit SR-C(FIGS. 8 and 14)supplies the ground voltage Vss to the other end portion of the driveelectrode TL(1) corresponding to the unit selection circuit USR(1) basedon the selection signals from the unit selection circuits USR(1) andUSR(3), and supplies the drive signal TSVCOM to the other end portion ofthe drive electrode TL(3) corresponding to the unit selection circuitUSR(3). Accordingly, the magnetic field generated around the driveelectrode TL(1) and the magnetic field generated around the driveelectrode TL(3) are superimposed on each other in the area of the driveelectrode TL(2).

When the drive electrode TL(0) is caused to generate the strong magneticfield, the unit drive circuits USL(dU), USR(dU), USL(1) and USR(1)illustrated in FIG. 23 output the selection signal indicating theselection. In response to this, the selection circuit SL-C supplies thedrive signal TSVCOM to the one end portion of the external area driveelectrode TL(dLU), and supplies the ground voltage Vss to the one endportion of the drive electrode TL(1). In addition, the selection circuitSR-C supplies the ground voltage Vss to the other end portion of theexternal area drive electrode TL(dLU), and supplies the drive signalTSVCOM to the other end portion of the drive electrode TL(1).Accordingly, the currents I1 and I2 indicated by the arrows in FIG. 23flow, the magnetic field is generated, and it is possible to generatethe strong magnetic field in the area of the drive electrode TL(0).

When the drive electrode TL(p) is caused to generate the strong magneticfield, the unit drive circuits USL(dD), USR(dD), USL(p−1) and USR(p−1)illustrated in FIG. 24 output the selection signal indicating theselection. In response to this, the selection circuit SL-C supplies theground voltage Vss to the one end portion of the external area driveelectrode TL(dLD), and supplies the drive signal TSVCOM to the one endportion of the drive electrode TL(p−1). In addition, the selectioncircuit SR-C supplies the drive signal TSVCOM to the other end portionof the external area drive electrode TL(dLU), and supplies the groundvoltage Vss to the other end portion of the drive electrode TL(p−1).Accordingly, the currents I1 and I2 indicated by the arrows in FIG. 24flow, the magnetic field is generated, and it is possible to generatethe strong magnetic field in the area of the drive electrode TL(p).

Of course, the external area drive electrode may be arranged only on oneside of the display panel 2.

In the second embodiment, it is possible to reduce an area where thedetection accuracy is decreased, within the area (the area of thedisplay panel 2) where the display is performed.

Third Embodiment

In the display device 1, display is performed in the display panel 2,and detection on whether an external proximity object such as a pen anda finger touches inside an area of the display panel 2 or the like isperformed simultaneously. In a third embodiment, the detection onwhether the external proximity object touches inside the area of thedisplay panel 2 or the like is performed by executing detection steps ofa plurality of stages during one frame period that performs the displayin the display panel 2. Here, a description will be given regarding anexample where the touch of the external proximity object is detected byexecuting the detection steps of two stages during one frame period.

The detection steps of two stages include a detection step at a firststage and a detection step at a second stage which is executed after thedetection step at the first stage. In the detection step at the firststage, the detection on whether an object, for example, the pen, whichcan be detected by magnetic field touch detection as the externalproximity object, touches the area of the display panel 2 is roughlyperformed. When it is detected that the pen as the external proximityobject touches the area of the display panel 2 in the detection step atthe first stage, the magnetic field touch detection to detect acoordinate, a distance or the like of the touch is finely performed. Onthe other hand, when the touch by the pen is not detected in thedetection step at the first stage, electric field touch detection isperformed. This finely performed magnetic field touch detection orelectric field touch detection becomes the detection step at the secondstage. Accordingly, if any of the pen and the finger touches inside thearea of the display panel 2, the touch can be detected during the oneframe period in which the display is being performed.

The detection step at the second stage is realized by the touchdetection semiconductor device 6 (FIG. 8) and the drive semiconductordevice DDIC (FIG. 8) although not particularly limited thereto. That is,the control circuit T-CNT inside the touch detection semiconductordevice 6 divides the one frame period into a first period and a secondperiod subsequent thereto, and instructs the magnetic field touchdetection using the magnetic field enable signal SC_EN in the firstperiod. In addition, the selection drive circuits SSL and SSR arecontrolled using the control signal Y-CNT in the first period so thatthe magnetic field touch detection is roughly performed. In the firstperiod, the control circuit D-CNT inside the drive semiconductor deviceDDIC is notified of whether the touch by the pen is detected by thecontrol signal SW sent from the touch detection semiconductor device 6.In the first period, the selection drive circuits SSL and SSR arecontrolled by the control signal Y-CNT so that the magnetic field touchdetection is roughly performed.

When the touch by the pen is detected during the magnetic field touchdetection in the detection step at the first stage, the control circuitD-CNT inside the drive semiconductor device DDIC instructs the magneticfield touch detection using the magnetic field enable signal SC_EN evenin the second period. In this case, the selection drive circuits SSL andSSR are controlled by the control signal Y-CNT in the second period sothat the magnetic field touch detection is finely performed.Accordingly, the detection of touch by the pen is performed in thesecond period.

On the other hand, when the touch by the pen is not detected during themagnetic field touch detection in the detection step at the first stage,the control circuit D-CNT inside the drive semiconductor device DDICinstructs the electric field touch detection using the electric fieldenable signal TC_EN in the second period. Accordingly, the electricfield touch detection is performed, and the detection of touch by thefinger is performed in the second period.

Although the description has been given regarding the example where thedrive semiconductor device DDIC executes the detection steps at the twostages based on the control signal SW sent from the touch detectionsemiconductor device 6, the invention is not limited thereto. Forexample, the touch detection semiconductor device 6 may execute controlof the detection steps at the two stages so that the magnetic fieldenable signal SC_EN, the electric field enable signal TC_EN, and thelike are outputted from the drive semiconductor device DDIC by thecontrol signal SW.

A difference between the rough magnetic field touch detection and thefine magnetic field touch detection is a difference in the number ofdrive electrodes sandwiched between drive electrodes to which a drivesignal is supplied in the magnetic field generation period TGT. That is,the number of drive electrodes sandwiched between the drive electrodesin the case of the rough magnetic field touch detection is larger thanthat in the case of the fine magnetic field touch detection in themagnetic field generation period TGT. For example, in the case of therough magnetic field touch detection, the drive signal TSVCOM issupplied to a pair of drive electrodes with 32 drive electrodessandwiched therebetween as described in the first and secondembodiments. In regard to this, in the case of the fine magnetic fieldtouch detection, the drive signal TSVCOM is supplied to a pair of driveelectrodes that sandwiches drive electrodes equal to or more than oneand smaller than 32 as described in the first and second embodiments.

For example, when the number of drive electrodes to which the drivesignal TSVCOM is supplied is the same at the rough magnetic field touchdetection and the fine magnetic field touch detection, it is possible todetect the touch by the pen in the entire area of the display panel 2for a short time by performing the rough magnetic field touch detection.On the other hand, a distance between the pair of drive electrodes towhich the drive signal is supplied becomes short in the case of the finemagnetic field touch detection, and so it is possible to generate astrong magnetic field and to achieve the improvement of the detectionaccuracy. When the magnetic field touch detection is performed in bothof the first period and the second period, the first period can beregarded as the rough magnetic field touch detection period, and thesecond period can be regarded as the fine magnetic field touch detectionperiod.

In addition, the magnetic field to be generated may be strengthened byincreasing the number of drive electrodes to which the drive signal issupplied during the rough touch detection. As described with referenceto FIG. 13B, for example, each of the pair of drive electrodes to whichthe drive signal TSVCOM is supplied may be provided as a bundleconfigured using a plurality of drive electrodes.

When the touch by the pen is not detected in the first period, theelectric field touch detection is performed so that the touch by thefinger is detected in the second period. Thus, it is also possible todetect the touch by the finger.

The detection of touch is performed with respect to the entire area ofthe display panel 2 in each of the first period and the second period.Thus, the entire area of the display panel 2 can be regarded as beingsubjected to the touch detection twice during one frame period. Whenbeing regarded in this manner, the touch detection at the first time isthe magnetic field touch detection and the touch detection at the secondtime is the magnetic field touch detection or the electric field touchdetection.

FIGS. 25A to 25I are timing diagrams illustrating operations of thedisplay device 1 according to the third embodiment. In FIGS. 25A to 25I,the horizontal axis represents time t. FIG. 25A is the timing diagramillustrating a frame signal F. The drive semiconductor device DDICperforms display on the display panel 2 according to the frame signal F.That is, the drive semiconductor device DDIC performs the display withrespect to the entire area of the display panel 2 during one period TFof the frame signal F. In other words, the display for one screen isperformed during one frame period (TF).

FIG. 25B is the timing diagram illustrating the one period (one frameperiod) TF of the periodical frame signal F. In FIG. 25B, numeral TF1represents a first period which starts in response to the frame signalF, and numeral TF2 represents a second period which is subsequent to thefirst period TF1. When the display is performed in the display device 1,the frame period TF illustrated in FIG. 25B is repeated, and so thefirst period TF1 and the second period TF2 are alternately generated inthis order.

FIG. 25C is the timing diagram schematically illustrating the displayperiod and the touch detection period. In FIG. 25C, each of periods DPS1to DPSp filled with the oblique line represents the display period.Incidentally, reference signs are attached only to DPS1, DPS2, DPSn toDPSn+2 and DPSp regarding the display period in FIG. 25C to prevent thedrawing from being complicated. In each of the display periods DPS1 toDPSp, the image information is supplied from the drive semiconductordevice DDIC to the signal line, the scan line becomes a high level, andso the image information is displayed on the display panel 2. As thedisplay is performed in each of the display periods DPS1 to DPSp, thedisplay for one screen is performed.

In FIG. 25C, numerals CSS11 to CSS1 p and CSS21 to CSS2 p represent thetouch detection periods. Here, numerals CSS11 to CSS1 p represent thetouch detection periods executed in the first period TF1, and numeralsCSS21 to CSS2 p represent the touch detection periods executed in thesecond period TF2. The rough magnetic field touch detection is performedin each of the touch detection periods CSS11 to CSS1 p, and thedetection of touch by the pen is performed with respect to the entirearea of the display panel 2 as the magnetic field touch detection isperformed in each of the touch detection periods CSS11 to CSS1 p.

The fine magnetic field touch detection or the electric field touchdetection is performed in each of the touch detection periods CSS21 toCSS2 p. As the touch detection is performed in each of the touchdetection periods CSS21 to CSS2 p, the detection of touch by the pen orthe finger is performed with respect to the entire area of the displaypanel 2.

Since the rough magnetic field touch detection is performed in each ofthe touch detection periods CSS11 to CSS1 p, it is possible to detectthe touch with respect to the entire area of the display panel 2 at asmall number of times. Thus, the touch detection on the entire area iscompleted at time tp before the display for one screen is completed.Accordingly, the time to perform the touch detection targeting theentire area of the display panel 2 can be secured until the display forone screen is completed. As a result, the touch detection on the entirearea is performed again in the touch detection periods CSS21 to CSS2 pfrom the time tp.

FIG. 25D to FIG. 25I are the timing diagrams illustrating the drivesignal TSVCOM which is supplied to the drive electrodes TL(n) to TL(n+5)arranged on the display panel 2.

The drive signal is supplied to each of the drive signals TL(n) toTL(n+5) from the selection drive circuits SSL and SSR illustrated inFIG. 8. In FIG. 25D to FIG. 25I, each left side illustrates the drivesignal which is supplied to the drive electrodes TL(n) to TL(n+5) in thetouch detection period CSS12, and each right side illustrates the drivesignal which is supplied to the drive electrodes TL(n) to TL(n+5) in thetouch detection period CSS24.

For example, the drive signal TSVCOM is supplied to one end portion ofthe drive electrode TL(n) from the selection drive circuit SSL, and theground voltage Vss is supplied to one end portion of the drive electrodeTL(n+5) in the touch detection period CSS12. At this time, the groundvoltage Vss is supplied to the other end portion of the drive electrodeTL(n) from the selection drive circuit SSR, and the drive signal TSVCOMis supplied to the other end portion of the drive electrode TL(n+5).Accordingly, the magnetic field is generated around each of the driveelectrode TL(n) and the drive electrode TL(n+5). The generated magneticfields are superimposed on each other in an area of the drive electrodesTL(n+1) to TL(n+4) which are sandwiched between the drive electrodeTL(n) and the drive electrode TL(n+5).

On the other hand, for example, the drive signal TSVCOM is supplied tothe one end portion of the drive electrode TL(n) from the selectiondrive circuit SSL, and the ground voltage Vss is supplied to one endportion of the drive electrode TL(n+2) in the touch detection periodCSS24. At this time, the ground voltage Vss is supplied to the other endportion of the drive electrode TL(n) from the selection drive circuitSSR, and the drive signal TSVCOM is supplied to the other end portion ofthe drive electrode TL(n+2). Accordingly, the magnetic field isgenerated around each of the drive electrode TL(n) and the driveelectrode TL(n+2). The generated magnetic fields are superimposed oneach other in an area of the drive electrode TL(n+1) which is sandwichedbetween the drive electrode TL(n) and the drive electrode TL(n+2). Sinceonly the drive electrode TL(n+1) is sandwiched between the driveelectrodes to which the drive signal TSVCOM is supplied, a distancebetween the drive electrodes becomes short, and the magnetic fieldobtained through the superimposition of the magnetic field becomesstrong. As a result, it is possible to achieve the improvement of thedetection accuracy.

In addition, the drive signal TSVCOM may be supplied to the driveelectrodes TL(n) and TL(n+1) from the selection drive circuit SSL, andthe drive signal TSVCOM may be supplied to the drive electrodes TL(n+4)and TL(n+5) from the selection drive circuit SSR in the touch detectionperiod CSS12. That is, two (a plurality of) drive electrodes may be usedas a bundle to supply the drive signal TSVCOM at the time of roughmagnetic field touch detection. Accordingly, it is possible tostrengthen the magnetic field to be generated and to achieve theimprovement of the detection accuracy even at the time of rough magneticfield touch detection.

Although the description has been given regarding the example where themagnetic field touch detection is performed in each of the touchdetection periods CSS21 to CSS2 p, the electric field touch detection isperformed in each of the touch detection periods CSS21 to CSS2 p when notouch by the pen is detected in the first period TF1. Accordingly, it ispossible to detect whether the finger touches the entire area of thedisplay panel 2 or the like in the second period TF2

The switch between the rough magnetic field touch detection and the finemagnetic field touch detection using the control signal Y-CNT can beachieved by controlling the switch control circuits SWL and SWR using aswitching control signal based on the control signal Y-CNT, for example.When the switching control signal indicates the rough magnetic fieldtouch detection, it is possible to perform the rough magnetic fieldtouch detection by causing the switch control circuits SWL and SWR tosupply the drive signal TSVCOM and the ground voltage Vss to a pair ofdrive electrodes arranged to sandwich a drive electrode corresponding toa unit drive circuit, which outputs the selection signal indicatingselection, and a drive electrode next to this drive electrode.

In addition, when the unit drive circuits correspond to the respectivedrive electrodes as illustrated in FIG. 22, it is possible to achievethe switch between the rough magnetic field touch detection and the finemagnetic field touch detection by changing a timing to supply theselection information SEI indicating the selection to a shift registerconfigured by the unit drive circuits.

<Magnetic Field Touch Detection Operation>

FIGS. 26A to 26F are timing diagrams illustrating each relationshipbetween the touch detection period and the display period. Asillustrated in FIGS. 25A to 25I, the touch detection periods CSS11 toCSS1 p, CSS21 to CSS2 p and the display periods DPS1 to DPSp arealternately generated. In FIGS. 26A to 26F, exemplified is a case wherethe display period is generated after the touch detection period. Inaddition, the touch detection period is indicated by reference sign CSSto collectively illustrate the touch detection periods CSS11 to CSS1 p,CSS21 to CSS2 p, and the display period is indicated by reference signDPS to collectively illustrate the display periods DPS1 to DPSp in FIGS.26A to 26F. Further, FIGS. 26A to 26F illustrate a case where themagnetic field touch detection is performed in the touch detectionperiod CSS. Incidentally, the horizontal axis represents the time t alsoin FIGS. 26A to 26F.

FIG. 26A is the schematic timing diagram illustrating the configurationof the magnetic field touch detection which is performed in the touchdetection period CSS. The touch detection period includes the magneticfield generation period TGT, the magnetic field detection period TDT,and a precharge period RST. In the precharge period RST, each voltage ofthe drive electrodes TL(0) to TL(p), the signal lines SL(0) to SL(p),and the like is precharged to a predetermined value in order for thedisplay period DPS to be subsequently generated.

As described above, the magnetic field generation period TGT is theperiod to generate the magnetic field, and the magnetic field detectionperiod TDT is the period to detect the magnetic field from the pen bythe magnetic field detection coil. The control circuit D-CNT illustratedin FIG. 8 changes the magnetic field enable signal SC_EN from a highlevel to a low level in the touch detection period CSS as illustrated inFIG. 26C. Accordingly, the magnetic field touch detection is designated.In addition, the control circuit D-CNT causes the drive signal TSVCOM toperiodically change in the magnetic field generation period TGT asillustrated in FIG. 26B. Accordingly, as described above, the drivesignal TSVCOM is supplied to each of the pair of drive electrodesarranged with the drive electrode sandwiched therebetween, the magneticfield depending on the change of the drive signal TSVCOM is generated,and the superimposition of the magnetic field is performed in the areaof the drive electrode sandwiched between the pair of drive electrodes.

The capacitive element inside the pen is charged by the magnetic fieldgenerated in the magnetic field generation period TGT. When there is thetouch of the pen, the magnetic field generated by the pen is detected bythe magnetic field detection coil in the magnetic field detection periodTDT, and the detection signal depending on the detected magnetic fieldis outputted from the magnetic field detection coil. In addition, thecontrol circuit D-CNT sets the drive signal TSVCOM to the predeterminedvoltage, and sets the magnetic field enable signal SC_EN to the highlevel as illustrated in FIG. 26B in the display period DPS.

Next, an example of the detection circuit to perform the detection onwhether the pen touches or not based on the detection signal sent fromthe magnetic field detection coil will be described with reference toFIG. 27. Although the detection circuit to detect the touch isconfigured using the amplifier circuit AMP and the touch semiconductordevice 6 in FIG. 8, here, the detection circuit using a microcontrollerMCU will be exemplified.

FIGS. 26D to 26F are the timing diagrams for describing the operation ofthe detection circuit illustrated in FIG. 27. Thus, FIGS. 26D to 26Fwill be referred to while describing the configuration and operation ofthe detection circuit illustrated in FIG. 27.

In FIG. 27, numeral MPX represents a multiplexer (selector) providedwith a plurality of switches SWA0 to SWAp. As described in the firstembodiment, magnetic field detection coils CY(0) to CY(p) are configuredusing the signal lines SL(0) to SL(p) or the detection electrodes RL(0)to RL(p) in the magnetic field detection period TDT. One end portion ofeach of the magnetic field detection coils is connected to each one endportion of the corresponding switches SWA0 to SWAp, and each of theother end portions thereof is connected to the ground voltage Vss. Asdescribed in FIG. 19 and the like, for example, the one end portion ofthe magnetic field detection coil CY(0), which is formed by connectingtwo signal lines arranged in parallel to each other, is connected to theone end portion of the switch SWA0, and the other end portion thereof isconnected to the ground voltage Vss. The remaining magnetic fielddetection coils CY(1) to CY(p) are also connected between the one endportion of each of the corresponding switches SWA1 to SWAp and theground voltage Vss in the same manner.

In addition, the other end portion of each of the switches SWA0 to SWApis connected to a node nA. Any of the switches SWA0 to SWAp is selectedand turned into the on-state in the magnetic field detection period TDT.This selection is performed by the microcontroller MCU. That is, any ofthe switches SWA0 to SWAp is selected and turned into the on-state by aselection signal sent from the microcontroller MCU. FIG. 26D illustratesa waveform of a selection signal SC_SEL which turns one of the switchesSWA0 to SWAp into the on-state. In FIG. 26D, the switch is turned intothe on-state as the selection signal SC_SEL is changed from the highlevel to the low level.

When any of the switches SWA0 to SWAp is turned into the on-state in themagnetic field detection period TDT, a detection signal in the magneticfield detection coil is transmitted to the node nA. A detection signalin the node nA is supplied to a gain circuit, and amplified by the gaincircuit. The amplified detection signal is supplied to a filter circuitin order to remove noise, and an output of the filter circuit isrectified by a rectifier circuit, and is supplied to an integratingcircuit. An output of the integrating circuit is supplied to themicrocontroller MCU.

Although not illustrated in Figure, the microcontroller MCU includes ananalog/digital conversion circuit, a clock signal generation circuit, anon-volatile memory in which a program is stored, and a processing unitthat operates according to the program stored in the non-volatilememory. The above-described output from the integrating circuit issupplied to the analog/digital conversion circuit via a terminal ADC ofthe microcontroller MCU, and is converted into a digital signal. Thedigital signal obtained through the conversion is processed by theprocessing unit, and the determination is performed on whether the penis proximate to any one of the coils CY(0) to CY(p).

The processing unit inside the microcontroller MCU forms a controlsignal according to the program. The control signal includes theselection signal to select the switches SWA0 to SWAp, an enable signalEN, and a reset signal rst. Further, the clock signal MCLK with aperiodically changing voltage is generated by the clock signalgeneration circuit inside the microcontroller MCU.

The clock signal MCLK is supplied to a buffer circuit BF. The buffercircuit BF is controlled by the enable signal EN. When the enable signalEN is a high level, the clock signal MCLK is supplied to the node nA viaa resistance R11. On the other hand, an output of the buffer circuit BFis set to a high-impedance state (Hi-Z) when the enable signal EN is alow level.

The gain circuit includes resistances R8 to R10, an operationalamplifier OP4, and a capacitive element CP3 for cut-off of directcurrent. The detection signal is supplied to a positive phase input (+)of the operational amplifier OP4, and an inverting input (−) of theoperational amplifier OP4 is connected to the ground voltage Vss via theresistance R9, and is connected to an output of the operationalamplifier OP4 via the resistance R8.

The filter circuit includes resistances R4 to R7, a capacitive elementCP2, and an operational amplifier OP3. A positive phase input (+) of theoperational amplifier OP3 is connected to the ground voltage Vss via theresistance R7, and an output signal from the gain circuit is suppliedvia the capacitive element CP2. In addition, an inverting input (−) ofthe operational amplifier OP3 is supplied to the ground voltage Vss viathe resistance R6, and is connected to the output of the operationalamplifier via the resistance R5. Further, the output of the operationalamplifier OP3 is connected to an input of the filter circuit via theresistance R4.

The rectifier circuit includes resistances R1 to R3, an operationalamplifier OP2, and a diode D. A positive phase input (+) of theoperational amplifier is connected to the ground voltage Vss via theresistance R3, and an output from the filter circuit is supplied to aninverting input (−) of the operational amplifier OP2 via the resistanceR2. Further, the output of the rectifier circuit is supplied via theresistance R1. An output of the operational amplifier OP2 is outputtedvia the diode D.

The integrating circuit includes a capacitive element CP1, a switch SWAAwhich receives the reset signal rst as the switch control signal, and anoperational amplifier OP1. A positive phase input (+) of the operationalamplifier is connected to the ground voltage Vss, and an inverting input(−) is connected to the output of the integrating circuit via thecapacitive element CP1. Further, the switch SWAA is connected betweenthe output and input of the integrating circuit.

In FIGS. 26A to 26F, the reset signal rst becomes the low level at timet0. Accordingly, the switch SWAA is turned into the off-state, and thereset is released. At this time, the microcontroller MCU sets the enablesignal EN to the high level. Accordingly, the clock signal CLK issupplied from the buffer circuit BF to the node nA via the resistanceR11.

The clock signal CLK supplied to the node nA is also supplied to thegain circuit. An output OUT1 of the gain circuit is changed according toa voltage change of the clock signal MCLK, and thus is changed asillustrated in FIG. 26E. The output OUT1 of the gain circuit is suppliedto the rectifier circuit via the filter circuit, and the rectifiedoutput is supplied to the integrating circuit. A voltage of the node nAis periodically changed from time t0 to time t1, but is not changed interms of an envelope curve, and thus the output of the integratingcircuit becomes a constant value.

The microcontroller MCU sets the enable signal EN to the low level atthe time t1. Accordingly, the node nA is set to the high-impedance state(Hi-Z). In addition, a switch SWA3 corresponding to the coil CY(3), forexample, is turned into the on-state by the selection signal SC_SEL(FIG. 26D) at the time t1. Accordingly, one end portion of the coilCY(3) is in the state of being connected to the node nA.

At this time, as the pen is present in the vicinity of the coil CY(3),the induced voltage is generated in the coil inside the pen by themagnetic field generated in the magnetic field generation period TGTbetween the time t0 and t2, and the capacitive element C (FIG. 2) ischarged.

In the time t1, the coil L1 inside the pen generates the magnetic fieldbased on the electric charge amount charged in the capacitive element C.The induced voltage is generated in the coil CY(3) according to a changeof the magnetic field generated by the coil L1.

As a result, the output OUT1 of the gain circuit is attenuated whileoscillating as illustrated in FIG. 26E. That is, the voltage isattenuated in terms of an envelope curve. Since the output OUT1 of thegain circuit is attenuated while oscillating from the time t1, theoutput OUT2 of the integrating circuit gradually increases asillustrated in FIG. 26F. The microcontroller MCU converts the outputOUT2 of the integrating circuit into a digital signal, and determinesthat the pen is present. At this time, the microcontroller MCU graspsthe switch turned into the on-state among the switches SWA0 to SWApusing the selection signal SC_SEL, and so is capable of grasping aposition of the selected magnetic field generation coil. Therefore, itis possible to determine the position at which the pen is present, thatis, the touched position, the pen pressure of the pen, and the like froma value of the digital signal obtained by the conversion and from thegrasped position of the magnetic field detection coil. It is possible todetermine the presence or absence of the pen, the writing pressure, andthe like by repeating the above-described operations.

In the detection circuit illustrated in FIG. 27, the gain circuit, thefilter circuit, the rectifier circuit and the integrating circuit can beshared among the plurality of magnetic field detection coils CY(0) toCY(p), and it is possible to suppress the increase of an area occupiedby the detection circuit.

Fourth Embodiment

FIG. 28 is a plan view illustrating a configuration of the displaydevice 1 according to a fourth embodiment. FIG. 28 illustrates theschematic plan view of the display panel 2.

In FIG. 28, numerals Tx1−1 to TxN−M represent drive electrodes(detection electrodes) which are arranged in a dot matrix form in thedisplay panel 2. Whether there is touch by a finger, for example, isdetected as a change of an electric charge amount by the driveelectrodes arranged in the dot matrix form. In FIG. 28, the driveelectrodes arranged in five rows and five columns are exemplified amongthe drive electrodes arranged in the dot matrix form. In addition,numerals SDL(1) to SDL(m) represent detection signal lines, and numeralsGL(1) to GL(n) represent scan lines. The detection signal lines SDL(1)to SDL(m) are arranged in parallel to the signal lines SL(0) to SL(p)(not illustrated) in the display panel 2. When the description is givenwith reference to FIG. 10, for example, the signal lines SL(n−6) toSL(n+9) extend in the column direction and are arranged in parallel inthe row direction, and the detection signal lines SDL(1) to SDL(m)extend in the column direction and are arranged in parallel in the rowdirection similarly to the signal lines SL(0) to SL(p).

The respective drive electrodes Tx1-1 to TxN-M arranged in the dotmatrix form are connected to the detection signal lines SDL(1) to SDL(m)having one-to-one correspondence. For example, the drive electrodesTx1-1, Tx1-2, Tx1-3, Tx1-17 and Tx1-M, which are arranged on the firstrow of the dot matrix, are connected to the detection signal linesSDL(1), SDL(n+1), SDL(2 n+1), SDL(+1) and SDL(m-n) having one-to-onecorrespondence. In addition, the drive electrodes TxN-1, TxN-2, TxN-3,TxN-17 and TxN-M, which are arranged on the N-th row of the dot matrix,are connected to the detection signal lines SDL(n), SDL(2 n), SDL(3 n),SDL(+n) and SDL(m) having one-to-one correspondence.

In the fourth embodiment, detection of touch by the finger is performedby detecting a signal change in each of the detection signal linesSDL(1) to SDL(m). In this case, each of the detection signal lines hasone-to-one correspondence with the drive electrodes, and so it ispossible to grasp the touched position by detecting the signal change inthe detection signal lines SDL(1) to SDL(m).

FIG. 29 is a circuit diagram illustrating a principle of touch detectionin the case of using the drive electrodes Tx1-1 to TxN-M arranged in thedot matrix form. Here, the description will be given by exemplifying thedrive electrode TxN-M. In FIG. 29, numeral OP5 represents an operationalamplifier, numeral CP5 represents a capacitive element, and numeralsSWD1 to SWD3 represents switches.

A parasitic capacitance C2 is present between the drive electrode TxN-Mand the ground voltage Vss. First, the switch SWD3 is turned into theon-state, and the switches SWD1 and SWD2 are turned into the off-state.Accordingly, electric charges stored in the capacitive element CP5 aredischarged via the switch SWD3. Next, the switch SWD3 is turned into theoff-state, and the switch SWD1 is turned into the on-state. At thistime, when the drive electrode TxN-M is touched by the finger, theelectric charges are also charged by the capacitance with the finger.

Next, the switch SWD1 is turned into the off-state, and the switch SWD2is turned into the on-state. Both inputs of the operational amplifierOP5 virtually become the same potential (the ground voltage Vss in FIG.29) by feedback of the capacitive element CP5, and so the electriccharges stored in the drive electrode TxN-M are shifted to thecapacitive element CP5. Thus, if the finger touches the drive electrodeTxN-M, the electric charges to be shifted to the capacitive element CP5increase. As a result, an absolute value of a voltage outputted from theoperational amplifier OP5 becomes larger. The voltage (signal) outputtedfrom the operational amplifier OP5 is changed depending on whether thefinger touches the drive electrode TxN-M. The presence or absence of thetouch by the finger is detected by this signal change. That is, thesignal outputted from the operational amplifier OP5 becomes a sensesignal S.

In this manner, it is possible to detect the touch by the finger bydetecting the signal change in each of the drive electrodes Tx1-1 toTxN-M. In a detection system illustrated in FIG. 29, the switch SWD1 isturned into the on-state; the drive signal is supplied to the driveelectrode (for example, TxN-M); and the signal change in the same driveelectrode TxN-M is detected, thereby detecting the touch by the finger.That is, the touch by the finger is detected based on the signal changein the drive electrode to which the drive signal has been supplied.Thus, it is a so-called capacitive self-detection system.

The scan lines GL(1) to GL(n) are arranged to be orthogonal to thedetection signal lines SDL(1) to SDL(m) and the signal lines SL(1) toSL(m) (not illustrated). In the fourth embodiment, the scan lines GL(1)to GL(n) are used as the signal wiring which generates the magneticfield at the time of magnetic field touch detection. That is, the scanlines GL(1) to GL(n) are used as the drive electrodes TL(0) to TL(p),which have been described in the first embodiment, in the magnetic fieldgeneration period TGT. Although not particularly limited, a plurality ofscan lines are collectively used as a single drive electrode. In theexample illustrated in FIG. 28, 20 scan lines are provided as a singlebundle. That is, the scan lines GL(1) to GL(20) are provided as abundle; the scan lines GL(21) to GL(40) are provided as a bundle; thescan lines GL(41) to GL(60) are provided as a bundle; the scan linesGL(61) to GL(80) are provided as a bundle; and the scan lines GL(n−19)to GL(n) are provided as a bundle.

The drive signal is supplied to the scan lines used as the bundle in themagnetic field generation period TGT, similarly to the first embodiment.For example, the drive signal TSVCOM is supplied to one end portion ofthe scan lines GL(1) to GL(20) used as the bundle from the side 2-L ofthe display panel 2 side, and the ground voltage Vss is supplied to theother end portion thereof from the side 2-R of the display panel 2 side.At this time, for example, the ground voltage Vss is supplied to one endportion of the scan lines GL(41) to GL(60) used as the bundle from theside 2-L of the display panel 2 side, and the drive signal TSVCOM issupplied to the other end portion thereof from the side 2-R of thedisplay panel 2 side. Accordingly, the magnetic field is generatedaround each of the bundle of the scan lines GL(1) to GL(20) and thebundle of the scan lines GL(41) to GL(60), and the magnetic fields aresuperimposed on each other in an area of the scan lines GL(21) toGL(40).

In the fourth embodiment, the drive electrodes Tx1-1 to TxN-M and thedetection signal lines SDL(1) to SDL(m) are formed on the TFT glasssubstrate TGB, and a magnetic field detection coil is configured usingthe detection electrodes RL(0) to RL(p) formed on the CF glass substrateCGB. The magnetic field detection coil, which is configured using thedetection electrodes RL(0) to RL(p) formed on the CF glass substrateCGB, has been described already with reference to FIG. 21, and so thedescription thereof will be omitted. In the fourth embodiment, thedetection of touch by the finger is performed by the drive electrodeswhich are formed on the TFT glass substrate TGB and arranged in the dotmatrix form. Thus, the detection electrodes RL(0) to RL(p) formed on theCF glass substrate CGB are not necessarily used for the detection oftouch by the finger, and so the detection electrodes RL(0) to RL(p) canbe fixed in a shape (for example, a coil shape) which is suitable fordetection of the magnetic field.

In addition, since the plurality of scan lines are handled as the bundlein the fourth embodiment, it is possible to reduce a combined resistanceof the scan lines in the magnetic field generation period TGT and tostrengthen the generated magnetic field.

First Modified Example

In FIG. 28, the description has been given regarding the case of usingthe detection electrodes RL(0) to RL(p) formed on the CF glass substrateCGB for the detection of the magnetic field. In a first modifiedexample, each of the detection electrodes Tx1-1 to TxN-M illustrated inFIG. 28 is used for the magnetic field detection. Accordingly, it isunnecessary to arrange the detection electrodes RL(0) to RL(p) for themagnetic field detection on the CF glass substrate CGB, and it ispossible to manufacture the display device 1 with low cost.

Second Modified Example

FIG. 38 is a plan view illustrating a configuration of the displaydevice 1 according to a second modified example of the fourthembodiment. FIG. 38 illustrates the schematic plan view of the displaypanel 2. FIG. 38 is similar to FIG. 28, and so a different point will bedescribed here.

In the second modified example illustrated in FIG. 38, detection signallines SDL(1)P to SDL(m)P, each of which is paired with the detectionsignal lines SDL(1) to SDL(m), extend in parallel to the paireddetection signal lines SDL(1) to SDL(m). In FIG. 28, reference signsSDL(1)P, SDL(2)P and SDL(n)P are attached only to the detection signallines, each of which is paired with the detection signal lines SDL(1),SDL(2) and SDL(n), and reference signs of the other detection signallines are not illustrated to prevent the drawing from being complicated.

Here, the description will be given by exemplifying one column (thedrive electrodes Tx1-1 to TxN-1) arranged at the leftmost side in FIG.38, and the other columns are also configured in the same manner. Thedetection signal line SDL(1) and the detection electrode SDL(1)P extendin parallel to each other and are connected to the drive electrodeTx1-1, and the detection signal line SDL(2) and the detection electrodeSDL(2)P also extend in parallel to each other and are connected to thedrive electrode Tx2-1. Hereinafter, the detection signal line SDL(n) andthe detection electrode SDL(n)P extend in parallel to each other and areconnected to the drive electrode TxN-1 in the same manner.

A magnetic field detection coil is formed using the detection signallines extending in parallel as a pair at the time of magnetic fieldtouch detection. For example, a magnetic field detection coil is formedusing the detection signal lines SDL(1) and SDL(1)P forming a pair; amagnetic field detection coil is formed using the detection signal linesSDL(2) and SDL(2)P forming as a pair; and a magnetic field detectioncoil is formed using the detection signal lines SDL(n) and SDL(n)Pforming as a pair. In this case, a signal change of one detection signallines, for example, the detection signal lines SDL(1), SDL(2) andSDL(n), among the detection signal lines each forming a pair isoutputted as the sense signal S. At this time, the ground voltage Vss issupplied to each of the other detection signal lines SDL(1)P, SDL(2)Pand SDL(n)P among the detection signal lines each forming the pair.

Since the magnetic field detection coil is formed using each of thedetection signal lines SDL(1) to SDL(m) and SDL(1)P to SDL(m)P, it isunnecessary to arrange the detection electrode for the magnetic fielddetection on the CF glass substrate CGB, and so it is possible tomanufacture the display device 1 with the low cost. In addition, theelectric field touch detection can be performed in the same manner asdescribed with reference to FIG. 28.

In addition, the magnetic field may be detected at the time of magneticfield touch detection using only a specific pair of detection signallines among the plurality of pairs of detection signal lines arranged onone column (the drive electrodes Tx1-1 to TxN-1). The detection signallines SDL(1) and SDL(1)P illustrated in FIG. 38 correspond to such aspecific pair of detection signal lines. Since the detection signallines SDL(1) and SDL(1)P are connected to the drive electrode Tx1-1arranged on the first row, the number of scan lines which are orthogonalthereto increases, and a detectable range at the time of magnetic fieldtouch detection becomes wide. Accordingly, the detection signal linesSDL(1) and SDL(1)P are suitably used for the magnetic field touchdetection. A pair of detection signal lines, which is connected to thedrive electrodes Tx1-2 to Tx1-M arranged on the first row among theplurality of pairs of detection signal lines included in the respectivecolumns, is used as the magnetic field detection coil at the time ofmagnetic field touch detection in the same manner for other columns ofthe dot matrix.

Third Modified Example

FIG. 39 is a plan view illustrating a configuration of the displaydevice 1 according to a third modified example of the fourth embodiment.FIG. 39 illustrates the schematic plan view of the display panel 2. FIG.39 is similar to FIG. 28, and so a different point will be describedhere.

In FIG. 28, the detection signal line extends to the area connected tothe corresponding drive electrode. In regard to this, each of thedetection signal lines SDL(1) to SDL(m) extends to cross the displaypanel 2 in the third modified example. For example, the detection signalline is arranged to extend from the side 2-D to the side 2-U of thedisplay panel 2. Here, the description will be given by exemplifying afirst column (the drive electrodes Tx1-1 to TxN-1) of the dot matrix,and other columns are also configured in the same manner.

The detection signal line SDL(1) extends from the side 2-D to the side2-U and is connected to the drive electrode Tx1-1 on the way to theextension, and the detection signal line SDL(2) also extends from theside 2-D and the side 2-U and is connected to the drive electrode Tx2-1on the way to the extension. Next, the detection signal line SDL(n) alsoextends from the side 2-D to the side 2-U and is connected to the driveelectrode TxN-1 on the way to the extension in the same manner.

On the side 2-U side, the switch SDS is connected between predetermineddetection signal lines. FIG. 39 illustrates only the switch SDSconnected between the detection signal lines SDL(1) and SDL(2), and theswitch SDS connected between the detection signal lines SDL(3) andSDL(n).

The switch SDS is turned into the on-state at the time of magnetic fieldtouch detection, similarly to the eighth switches k00 to kp illustratedin FIG. 19. Accordingly, a plurality of detection signal lines areconnected to each other. In the example of FIG. 39, the detection signallines SDL(1) and SDL(2) are connected to each other on the side 2-Uside. Accordingly, a magnetic field detection coil is formed using thedetection signal lines SDL(1) and SDL(2) at the time of magnetic fieldtouch detection. At this time, for example, the ground voltage Vss issupplied to the detection signal line SDL(2), and a signal change in thedetection signal line SDL(1) is outputted as the sense signal S.

Accordingly, since the magnetic field detection coil is formed using thedetection signal lines SDL(1) to SDL(m), it is unnecessary to arrangethe detection electrode for the magnetic field detection on the CF glasssubstrate CGB, and so it is possible to manufacture the display device 1with the low cost. In addition, the electric field touch detection canbe performed in the same manner as described with reference to FIG. 28.

Although the description has been given in FIG. 39 regarding the examplewhere the magnetic field detection coil is formed using the adjacentdetection signal lines SDL(1) and SDL(2), the invention is not limitedthereto. That is, the detection signal lines, which are arranged withthe detection signal lines sandwiched therebetween, may be connectedusing switches to form magnetic field detection coils that overlap eachother. In addition, a winding with one and half turns or more may beused instead of the winding with one turn.

Fourth Modified Example

FIG. 30 is a plan view illustrating a configuration of the displaydevice 1 according to a fourth modified example of the fourthembodiment. FIG. 30 is similar to FIG. 28, and so a different point willbe mainly described here. In FIG. 30, numerals SL(0) to SL(p) representthe signal lines. As described with reference to FIG. 28, the detectionsignal lines SDL(1) to SDL(m) are arranged in parallel to the signallines SL(0) to SL(p) on the display panel 2.

In this modified example, the signal lines SL(0) to SL(p) are used as asignal wiring to generate a magnetic field. Although not particularlylimited, the plurality of signal lines are collectively used as abundle, and the drive signal TSVCOM is supplied in the magnetic fieldgeneration period TGT in this modified example. When the description isgiven by exemplifying FIG. 30, the signal lines SL(0) to SL(19) arecollectively used as a bundle, the signal lines SL(20) to SL(39) arecollective used as a bundle, and the signal lines SL(40) to SL(59) arecollectively used as a bundle in the magnetic field generation periodTGT. In addition, the signal lines SL(k) to SL(k+19) are collectivelyused as a bundle, and the signal lines SL(p−19) to SL(p) arecollectively used as a bundle.

The drive signal is supplied to the bundled signal lines in the magneticfield generation period TGT. For example, the drive signal TSVCOM issupplied to one-end portions of the bundled signal lines SL(0) to SL(19)from the side 2-U of the display panel 2 side, and the ground voltageVss is supplied to the other-end portions thereof from the side 2-D ofthe display panel 2 side. At this time, for example, the ground voltageVss is supplied to one-end portions of the bundled signal lines SL(40)to SL(59) from the side 2-U of the display panel 2 side, and the drivesignal TSVCOM is supplied to the other-end portions thereof from theside 2-D of the display panel 2 side. Accordingly, a superimposedmagnetic field is formed in an area of the signal lines SL(20) to SL(39)in the magnetic field generation period TGT.

In this modified example, a magnetic field detection coil is configuredusing the detection electrodes RL(0) to RL(p) formed on the CF glasssubstrate CGB, for example. When the magnetic field detection coil isformed using the detection electrodes RL(0) to RL(p), each of thedetection electrodes RL(0) to RL(p) is formed to be orthogonal to eachof the signal lines SL(0) to SL(p) and to be parallel to each other, andpredetermined detection electrodes are connected to each other asillustrated in FIG. 21. In addition, the magnetic field detection coilmay be formed using the scan lines GL(0) to GL(p).

In addition, the magnetic field may be detected by the detectionelectrodes Tx1-1 to TxN-M. If the magnetic field is detected by thedetection electrodes Tx1-1 to TxN-M, for example, it is unnecessary toarrange the detection electrode for the magnetic field detection on theCF glass substrate CGB, and it is possible to manufacture the displaydevice 1 with the low cost.

Fifth Modified Example

FIG. 40 is a plan view illustrating a configuration of the displaydevice 1 according to a fifth modified example of the fourth embodiment.FIG. 40 is similar to FIG. 30, and so a different point will be mainlydescribed here. In the fifth modified example, detection signal linesSDL(1)L to SDL(m)L, which extend in parallel to the respective detectionsignal lines SDL(1) to SDL(m), are arranged. In FIG. 40, reference signsSDL(1)L, SDL(2)L and SDL(n)L are attached only to the detection signallines arranged at the drive electrodes Tx1-1 to TxN-1 on the firstcolumn in order to prevent the drawing from being complicated.

Here, the description will be given by exemplifying the drive electrodeson the first column, but the other columns are also configured in thesame manner. The detection signal line SDL(1)L extends in parallel tothe detection signal line SDL(1), and the detection signal line SDL(1)and the detection signal line SDL(1)L are connected to each other, in anarea of the drive electrode Tx1-1 to which the detection signal lineSDL(1) is connected, so as to form a loop LPP. In addition, thedetection signal line SDL(2)L extends in parallel to the detectionsignal line SDL(2), and the detection signal line SDL(2) and thedetection signal line SDL(2)L are connected to each other, in an area ofthe drive electrode Tx2-1 to which the detection signal line SDL(2) isconnected, so as to form a loop LPP. In the same manner after this, thedetection signal line SDL(n)L extends in parallel to the detectionsignal line SDL(n), and the detection signal line SDL(n) and thedetection signal line SDL(n)L are connected to each other, in an area ofthe drive electrode TxN-1 to which the detection signal line SDL(n) isconnected, so as to form a loop LPP.

Each loop LPP is formed by bending and connecting the detection signalsconnected to each other when seen in a plan view.

In the fifth modified example, each loop LPP functions as a magneticfield detection coil. That is, a signal change in one detection signalline out of the detection signal lines connected to each other isdetected as the sense signal S, and the ground voltage Vss is suppliedto the other detection signal line at the time of magnetic field touchdetection. Accordingly, when the vicinity of the drive electrode istouched by a pen, a signal change occurs in the detection signal lineforming the loop LPP in the area of the drive electrode by the magneticfield generated around the pen, and the touch by the pen and acoordinate thereof can be obtained.

For example, when each of the detection signal lines SDL(1)L, SDL(2)L toSDL(n)L is set as the other detection signal line between the detectionsignal lines forming each loop, the ground voltage Vss is supplied toeach of the detection signal lines SDL(1)L, SDL(2)L to SDL(n)L. At thistime, the signal change in each of the detection signal lines SDL(1) andSDL(2) to SDL(n), which serves as one detection signal line between thedetection signal lines forming each loop, is detected as the sensesignal S. Accordingly, it is possible to make the detection about whichpart of the first column the pen is touched at, and simultaneously tomake the detection about which row (which area out of the driveelectrodes Tx1-1 to TxN-1) of the first column the touch is performed at(in).

Since the detection signal line is also used as the magnetic fielddetection coil in the fifth modified example, it is possible tomanufacture the display device 1 with the low cost. In addition, theelectric field touch detection can be performed in the same manner asthe fourth modified example. Further, the detection signal line can beshared between the magnetic field detection and the electric fielddetection, and so it is possible to suppress the increase of price ofthe display device which is capable of the magnetic field touchdetection and the electric field touch detection.

Fifth Embodiment

In the first to fourth embodiments, the description has been givenmainly regarding the example where the magnetic field is generated inthe magnetic field generation period TGT using the signal wiringorthogonal to the signal lines SL(0) to SL(p) in the display panel 2. Ina fifth embodiment, the description will be given regarding an examplewhere a magnetic field is generated in the magnetic field generationperiod TGT using a signal wiring arranged in parallel to the signallines SL(0) to SL(p) in the display panel 2. Here, the description willbe given regarding a case where drive electrodes are used as the signalwiring arranged in parallel to the signal lines SL(0) to SL(p).

FIG. 31 is a plan view schematically illustrating a configuration of thedisplay device 1 according to the fifth embodiment. FIG. 31 illustratesa part relating to the display panel 2. Although the plurality of signallines SL(0) to SL(p), the plurality of scan lines GL(0) to GL(p), theplurality of drive electrodes TL(0) to TL(p) and the like are arrangedin the display panel 2. However, FIG. 31 illustrates the display panel 2in which the signal lines SL(0) to SL(7), the scan lines GL(0) to GL(3),and the drive electrodes TL(0) to TL(7) are arranged to make thedescription easy. The signal lines SL(0) to SL(7) extend in the columndirection and are arranged in parallel in the row direction in thedisplay panel 2. In the fifth embodiment, the drive electrodes TL(0) toTL(7) to which the drive signal is supplied in the magnetic fieldgeneration period TGT are arranged in parallel to the signal lines SL(0)to SL(7). That is, the drive electrodes TL(0) to TL(7) also extend inthe column direction and are arranged in parallel in the row directionin the display panel 2.

The scan lines GL(0) to GL(3) extend in the row direction and arearranged in parallel in the column direction in the display panel 2. Inthe fifth embodiment, gate drivers 5-1 and 5-2 are arranged along theside 2-L and the side 2-R of the display panel 2, respectively, althoughnot particularly limited thereto. The scan lines GL(0) to GL(3) areconnected to the gate driver 5-1 on the side 2-L side and are connectedto the gate driver 5-2 on the side 2-R side. When display is performedin the display panel 2, for example, the gate driver 5-1 supplies a scanline signal with a high level to the scan line GL(0), and the gatedriver 5-2 supplies the scan line signal with the high level to the nextscan line GL(1) at the next timing. That is, the scan line signal withthe high level is supplied to the scan lines GL(0) to GL(3) alternatelyfrom the gate drivers 5-1 and 5-2. Accordingly, it is possible toprevent the increase of the frame.

In FIG. 31, numeral 3 represents a signal line selector. The signal lineselector 3 has been described with reference to FIG. 8 and the like, andso the description thereof will be omitted. In FIG. 31, numerals SCW-Dand SCW-U represent connection circuits which electrically connect thesignal lines SL(0) to SL(7) and the common electrodes TL(0) to TL(7),which overlap each other when seen in a plan view, during the touchdetection. That is, the connection circuit SCW-D connects the driveelectrode TL(0) and the signal line SL(0) on the side 2-D side, and theconnection circuit SCW-U connects the drive electrode TL(0) and thesignal line SL(0) on the side 2-U side during the touch detection.Similarly, the drive electrode TL(1) and the signal line SL(1) areconnected by the connection circuits SCW-D and SCW-U during the touchdetection. Similarly, the remaining drive electrodes and signal linesare also electrically connected during the touch detection. Accordingly,the drive electrodes and the signal lines, which overlap each other whenseen in a plan view, are connected in parallel during the touchdetection, and it is possible to achieve the reduction of the combinedresistance.

In FIG. 31, numerals SU-R and SD-R represent drive circuits, andnumerals SU-C and SD-C represent selection circuits. Similarly to thefirst embodiment, a selection drive circuit (a first drive circuit or asecond drive circuit) SSU is configured using the drive circuit SU-R andthe selection circuit SU-C, and a selection drive circuit (a seconddrive circuit or a first drive circuit) SSD is configured using thedrive circuit SD-R and the selection circuit SD-C. The selection drivecircuit SSU is arranged along the side 2-U of the display panel 2, andthe selection drive circuit SSD is arranged along the side 2-D of thedisplay panel 2.

The selection drive circuit SSU supplies a drive signal from the side2-U side to one drive electrode out of the selected pair of driveelectrodes and supplies the ground voltage Vss to the other driveelectrode in the magnetic field generation period TGT for the magneticfield touch detection. In addition, the selection drive circuit SSDsupplies the ground voltage Vss from the side 2-D side to the otherdrive electrode out of the above-described pair of drive electrodes andsupplies the drive signal to the one drive electrode. Accordingly, astrong superimposed magnetic field is generated between the selectedpair of drive electrodes in the magnetic field generation period TGT.

In FIG. 31, numeral VCOM represents a voltage wiring to which apredetermined voltage VCOMDC is supplied. In addition, numeral TPLrepresents a voltage wiring to which the ground voltage Vss is supplied,and numeral TPH represents a voltage wiring to which a predeterminedvoltage (for example, the voltage Vp illustrated in FIGS. 15A to 15C) issupplied. The selection drive circuits SSU and SSD connect the voltagewiring TPL to the selected drive electrode in order to supply the groundvoltage Vss to the selected drive electrode. In addition, the selectiondrive circuits SSU and SSD connect the voltage wiring TPH to theselected drive electrode in order to supply the drive signal to theselected drive electrode.

A magnetic field detection coil is configured using the detectionelectrodes RL(0) to RL(p) formed on the CF glass substrate CGB, forexample. In the fifth embodiment, the detection electrodes RL(0) toRL(p) extend in the row direction and are arranged in parallel in thecolumn direction in the display panel 2, similarly to the scan line. Inaddition, the predetermined detection electrodes are connected to formthe magnetic field detection coil in the magnetic field detection periodTDT. In addition, the magnetic field detection coil may be formed usingthe scan lines GL(0) to GL(3).

In the fifth embodiment, the selection drive circuit SSD supplies thedrive signal to the selected drive electrode at the time of electricfield touch detection. Accordingly, an electric field is generatedaround the selected drive electrode. In this case, a change in theelectric field is detected by the detection electrodes RL(0) to RL(p) orthe scan lines GL(0) to GL(3) formed on the CF glass substrate CGB, forexample.

Incidentally, each of the gate drivers 5-1 and 5-2 has a function ofturning the scan lines GL(0) to GL(3) into the floating state, and turnsthe scan lines GL(0) to GL(3) into the floating state, for example, inthe magnetic field generation period TGT although not particularlylimited.

<Configuration of Selection Drive Circuit>

FIG. 32 is a circuit diagram illustrating each configuration of theselection drive circuits SSU and SSD according to the fifth embodiment.FIG. 32 is drawn in accordance with actual arrangement although beingschematic. FIG. 32 illustrates the drive electrodes TL(0) to TL(6) amongthe drive electrodes TL(0) to TL(7) illustrated in FIG. 31, and eachpart of the selection drive circuits SSU and SSD corresponding to thesedrive electrodes TL(0) to TL(6).

As illustrated in FIG. 31, the selection drive circuit SSU is arrangedalong the side 2-U of the display panel 2, and the selection drivecircuit SSD is arranged along the side 2-D of the display panel 2. Thedrive circuit SU-R inside the selection drive circuit SSU is providedwith unit drive circuits USU(0) to USU(6) which correspond to therespective drive electrodes TL(0) to TL(6) and which are arranged alongthe side 2-U. Similarly, the drive circuit SD-R inside the selectiondrive circuit SSD is provided with unit drive circuits USD(0) to USD(6)which correspond to the respective drive electrodes TL(0) to TL(6) andwhich are arranged along the side 2-D.

In the fifth embodiment, the voltage wirings TPL and TPH are arranged tosurround the display panel 2. When the description is given byexemplifying the module illustrated in FIG. 9, the voltage wirings TPLand TPH are arranged to pass through an area between the side 2-L of thedisplay panel 2 and the side 900-L of the module 900, an area betweenthe side 2-U of the display panel 2 and the side 900-U of the module900, an area between the side 2-R of the display panel 2 and the side900-R of the module 900, and an area between the side 2-D of the displaypanel 2 and the side 900-D of the module 900. That is, the voltagewirings TPL and TPH are arranged in upper, lower, right and left framesof the module 900. Meanwhile, the voltage wiring VCOM is arranged in thearea between the side 2-D of the display panel 2 and the side 900-D ofthe module 900.

The selection circuit SU-C inside the selection drive circuit SSU isprovided with unit selection circuits UUC(0) to UUC(6) which correspondto the respective unit drive circuits USU(0) to USU(6) in the fifthembodiment. Each of the unit selection circuits UUC(0) to UUC(6) isprovided with a tenth switch USW1 and an eleventh switch USW2. In eachof the unit selection circuits UUC(0) to UUC(6), the tenth switch USW1is connected between the voltage wiring TPH and one end portion of thecorresponding drive electrode and is subjected to switch control by aselection signal sent from the corresponding unit drive circuit; and theeleventh switch USW2 is connected between the voltage wiring TPL and oneend portion of the corresponding drive electrode and is subjected toswitch control by a selection signal sent from the corresponding unitdrive circuit.

That is, the tenth switch USW1 is connected between the voltage wiringTPH and one end portion of the drive electrode TL(0) and is subjected toswitch control by a selection signal C10 sent from the unit selectioncircuit USU(0) in the unit selection circuit UUC(0). In addition, theeleventh switch USW2 is connected between the voltage wiring TPL and theone end portion of the drive electrode TL(0) and is subjected to switchcontrol by a selection signal C20 sent from the unit selection circuitUSU(0) in the unit selection circuit UUC(0). In the unit selectioncircuit UUC(1), each of the tenth switch USW1 and the eleventh switchUSW2 is connected between each of the voltage wirings TPH and TPL andone end portion of the drive electrode TL(1) and is subjected to switchcontrol by each of selection signals C11 and C21 sent from the unitselection circuit USU(1). In the unit selection circuit UUC(2), each ofthe tenth switch USW1 and the eleventh switch USW2 is connected betweeneach of the voltage wirings TPH and TPL and one end portion of the driveelectrode TL(2) and is subjected to switch control by each of selectionsignals C12 and C22 sent from the unit selection circuit USU(2).

Similarly, each of the tenth switch USW1 and the eleventh switch USW2 isconnected between each of the voltage wirings TPH and TPL and one end ofthe drive electrode TL(3) and is subjected to switch control by each ofselection signals C13 and C23 sent from the unit selection circuitUSU(3) in the unit selection circuit UUC(3). Each of the tenth switchUSW1 and the eleventh switch USW2 is connected between each of thevoltage wirings TPH and TPL and one end portion of the drive electrodeTL(4) and is subjected to switch control by each of selection signalsC14 and C24 sent from the unit selection circuit USU(4) in the unitselection circuit UUC(4). Each of the tenth switch USW1 and the eleventhswitch USW2 is connected between each of the voltage wirings TPH and TPLand one end portion of the drive electrode TL(5) and is subjected toswitch control by each of selection signals C15 and C25 sent from theunit selection circuit USU(5) in the unit selection circuit UUC(5). Eachof the tenth switch USW1 and the eleventh switch USW2 is connectedbetween each of the voltage wirings TPH and TPL and one end portion ofthe drive electrode TL(6) and is subjected to switch control by each ofselection signals C16 and C26 sent from the unit selection circuitUSU(6) in the unit selection circuit UUC(6).

The drive circuit SD-R inside the selection drive circuit SSD is alsoprovided with the unit drive circuits USD(0) to USD(6) which correspondto the respective drive electrodes TL(0) to TL(6). In addition, theselection circuit SD-L is provided with unit selection circuits UDC(0)to UDC(6) which correspond to the respective drive electrodes and unitdrive circuits. Each of the unit selection circuits UDC(0) to UDC(6) isprovided with a twelfth switch USW3, a thirteenth switch USW4, and afourteenth switch USW5 which are subjected to switch control by controlsignals sent from the corresponding unit selection circuits. Here, thetwelfth switch USW3 is connected between the other end portion of thecorresponding drive electrode and the voltage wiring VCOM; thethirteenth switch USW4 is connected between the other end portion of thecorresponding drive electrode and the voltage wiring TPL; and thefourteenth switch USW5 is connected between the other end portion of thecorresponding drive electrode and the voltage wiring TPH.

That is, the twelfth switch USW3 is connected between the other endportion of the drive electrode TL(0) and the voltage wiring VCOM; thethirteenth switch USW4 is connected between the other end portion of thedrive electrode TL(0) and the voltage wiring TPL; and the fourteenthswitch USW5 is connected between the other end portion of the driveelectrode TL(0) and the voltage wiring TPH in the unit selection circuitUDC(0). In addition, the twelfth switch USW3 in the unit selectioncircuit UDC(0) is subjected to switch control by a selection signal S30sent from the unit drive circuit USD(0); the thirteenth switch USW4 issubjected to switch control by a selection signal S40 sent from the unitdrive circuit USD(0); and the fourteenth switch USW5 is subjected toswitch control by the selection signal S40 sent from the unit drivecircuit USD(0).

In addition, each of the twelfth switch USW3, the thirteenth switchUSW4, and the fourteenth switch USW5 is connected between the other endportion of the drive electrode TL(1) and each of the voltage wiringsVCOM, TPL and TPH and is subjected to switch control by selectionsignals S31 and S41 sent from the unit drive circuit USD(1) in the unitselection circuit UDC(1). Each of the twelfth switch USW3, thethirteenth switch USW4, and the fourteenth switch USW5 is connectedbetween the other end portion of the drive electrode TL(2) and each ofthe voltage wirings VCOM, TPL and TPH and is subjected to switch controlby selection signals S32 and S42 sent from the unit drive circuit USD(2)in the unit selection circuit UDC(2). In the unit selection circuitUDC(3), each of the twelfth switch USW3, the thirteenth switch USW4, andthe fourteenth switch USW5 is connected between the other end portion ofthe drive electrode TL(3) and each of the voltage wirings VCOM, TPL andTPH and is subjected to switch control by selection signals S33 and S43sent from the unit drive circuit USD(3).

Similarly, each of the twelfth switch USW3, the thirteenth switch USW4,and the fourteenth switch USW5 is connected between the other endportion of the drive electrode TL(4) and each of the voltage wiringsVCOM, TPL and TPH and is subjected to switch control by selectionsignals S34 and S44 sent from the unit drive circuit USD(4) in the unitselection circuit UDC(4). Each of the twelfth switch USW3, thethirteenth switch USW4, and the fourteenth switch USW5 is connectedbetween the other end portion of the drive electrode TL(5) and each ofthe voltage wirings VCOM, TPL and TPH and is subjected to switch controlby selection signals S35 and S45 sent from the unit drive circuit USD(5)in the unit selection circuit UDC(5). In addition, each of the twelfthswitch USW3, the thirteenth switch USW4, and the fourteenth switch USW5is connected between the other end portion of the drive electrode TL(6)and each of the voltage wirings VCOM, TPL and TPH and is subjected toswitch control by selection signals S36 and S46 sent from the unit drivecircuit USD(6) in the unit selection circuit UDC(6).

Figure is illustrated so that the thirteenth switch USW4 and thefourteenth switch USW5 are subjected to the switch control by the singleselection signal (for example, the selection signal S40) in each of theunit selection circuits UDC(0) to UDC(6) in order to prevent the drawingfrom being complicated, but the thirteenth switch USW4 and thefourteenth switch USW5 are separately switch-controlled by thecorresponding unit drive circuit.

In the fifth embodiment, the drive signal or the ground voltage Vss issupplied to the drive electrode corresponding to the unit drive circuitwhich indicates selection in the magnetic field generation period TGT,similarly to the description in FIG. 22. In this case, the drive signalcorresponds to the predetermined voltage in the voltage wiring TPH, andthe supply of the predetermined voltage of the voltage wiring TPH to thedrive electrode corresponds to the supply of the drive signal.

Each of the unit drive circuits USU(0) to USU(6) has a shift stage, andthe respective shift stages are connected in series in this order.Similarly, each of the unit drive circuits USD(0) to USD(6) also has ashift stage, and the respective shift stages are connected in series inthis order. For example, the selection information SEI indicating theselection is set to the unit drive circuits USU(0), USU(1), USD(0) andUSD(1), and the selection information SEI is sequentially shifted to theunit drive circuit USU(6) and USD(6) in synchronization with a clocksignal (not illustrated).

For example, when the selection information SEI indicating the selectionis set to the unit drive circuits USU(0), USU(1), USD(0) and USD(1), theunit drive circuit USU(0) turns the eleventh switch USW2 inside the unitselection circuit UUC(0) into the on-state using the selection signalS20, and turns the tenth switch USW1 into the off-state using theselection signal S10 in the magnetic field generation period TGT. Atthis time, the unit drive circuit USU(1) turns the tenth switch USW1inside the unit selection circuit UUC(1) into the on-state using theselection signal S11, and turns the eleventh switch USW2 into theoff-state using the selection signal S21.

In addition, at this time, the unit drive circuit USD(0) turns thefourteenth switch USW5 into the on-state using the selection signal S40,and turns the thirteenth switch USW4 into the off-state. In addition,the unit drive circuit USD(0) turns the twelfth switch USW3 into theoff-state using the selection signal S30. Further, at this time, theunit drive circuit USD(1) turns the thirteenth switch USW4 into theon-state using the selection signal S41, and turns the fourteenth switchUSW5 into the off-state. In addition, the unit drive circuit USD(1)turns the twelfth switch USW3 into the off-state using the selectionsignal S30.

Accordingly, the one end portion of the drive electrode TL(0) isconnected to the voltage wiring TPL via the eleventh switch USW2 insidethe unit selection circuit UUC(0), and the other end portion of thedrive electrode TL(1) is connected to the voltage wiring TPL via thethirteenth switch USW4 inside the unit selection circuit UDC(1). At thistime, the other end portion of the drive electrode TL(0) is connected tothe voltage wiring TPH via the fourteenth switch USW5 inside the unitselection circuit UDC(0); and the one end portion of the drive electrodeTL(1) is connected to the voltage wiring TPH via the tenth switch USW1inside the unit selection circuit UUC(1). As a result, the groundvoltage Vss is supplied to the one end portion of the drive electrodeTL(0) and the other end portion of the drive electrode TL(1); and thepredetermined voltage is supplied to the other end portion of the driveelectrode TL(0) and the one end portion of the drive electrode TL(1) asthe drive signal.

A current flows in the drive electrode TL(0) in a direction from theother end portion toward the one end portion thereof (upward directionin the drawing) by the predetermined voltage; a current flows in thedrive electrode TL(1) in a direction from the one end portion toward theother end portion (downward direction in the drawing); a magnetic fieldis generated around each of the drive electrodes TL(0) and TL(1); andthe magnetic fields are superimposed on each other in an area sandwichedbetween the drive electrodes TL(0) and TL(1).

Incidentally, each of the unit drive circuits USU(2) to USU(6) turns thetenth switch USW1 and the eleventh switch USW2 in each of thecorresponding unit selection circuits UUC(2) to UUC(6) into theoff-state using the selection signals S12 to S16 and S22 to S26 at thistime. In addition, each of the unit drive circuits USD(2) to USD(6)turns the twelfth switch USW3, the thirteenth switch USW4, and thefourteenth switch USW5 in each of the corresponding unit selectioncircuits UDC(2) to UDC(6) into the off-state using the selection signalsS32 to S36 and S42 to S46 at this time. As a result, each of the driveelectrodes TL(2) to TL(6) is turned into a high impedance state.

When the selection information SEI is shifted to the unit drive circuitsUSU(1), USU(2), UDC(1) and UDC(2) as the clock signal changes, the unitdrive circuit USU(1) turns the tenth switch USW1 inside the unitselection circuit UUC(1) into the off-state, and turns the eleventhswitch USW2 into the on-state using the selection signals S11 and S21.At this time, the unit drive circuit USU(2) turns the tenth switch USW1inside the unit selection circuit UUC(2) into the on-state and turns theeleventh switch USW2 into the off-state using the selection signals S11and S21. In addition, the unit selection circuit USD(1) turns thefourteenth switch USW5 inside the unit selection circuit UDC(1) into theon-state, and turns the twelfth switch USW3 and the thirteenth switchUSW4 into the off-state using the selection signals S31 and S41. Inaddition, the unit selection circuit USD(2) turns the thirteenth switchUSW4 inside the unit selection circuit UDC(2) into the on-state, andturns the twelfth switch USW3 and the fourteenth switch USW5 into theoff-state using the selection signals S32 and S42.

As a result, a current flows in the drive electrode TL(1) from the otherend portion toward the one end portion thereof and a current flows inthe drive electrode TL(2) from the one end portion toward the other endportion thereof. The magnetic fields are generated around the driveelectrodes TL(1) and TL(2) due to these currents, thereby generating thesuperimposed magnetic field. At this time, the tenth switch to thefourteenth switch in each of the unit selection circuits UUC(0), UUC(3)to UUC(6), UDC(0) and UDC(3) to UDC(6) are turned into the off-state,and the drive electrodes TL(0) and TL(3) to TL(6) are turned into thehigh impedance state.

After this, the magnetic field is sequentially generated according tothe shift of the selection information SEI toward the unit drivecircuits USU(6) and USD(6) in synchronization with the clock signal.That is, the magnetic fields are generated around the drive electrodesTL(2) and TL(3); the magnetic fields are generated around the driveelectrodes TL(3) and TL(4) at the subsequent timing; the magnetic fieldsare generated around the drive electrodes TL(4) and TL(5) at the furthersubsequent timing; and then the magnetic fields are generated around thedrive electrodes TL(5) and TL(6).

The direction of the current flowing in the drive electrode is notlimited to the above-described direction. For example, when the driveelectrodes TL(0) and TL(1) are caused to generate the magnetic fields,the current may flow in the drive electrode TL(0) in a direction fromthe one end portion toward the other end portion thereof, and flow inthe drive electrode TL(1) from the other end portion toward the one endportion thereof. That is, the respective directions of the currents maybe opposite to each other between the pair of drive electrodesadjacently arranged.

Although the description has been given regarding the example of usingthe drive electrodes arranged to be adjacent to each other, theinvention is not limited thereto. For example, the magnetic field may begenerated by the drive electrodes which are arranged to sandwich one ora plurality of drive electrodes. For example, the selection informationSEI indicating selection may be set to the unit drive circuits USU(0),USC(2), USD(0) and USD(2). In this manner, the magnetic field isgenerated around the pair of drive electrodes TL(0) and TL(2) arrangedto sandwich the drive electrode TL(1). Subsequently, the magnetic fieldsare sequentially generated around the drive electrodes arranged tosandwich one drive electrode as the selection information SEI is shiftedin synchronization with the change of the clock signal.

At the time of electric field touch detection, each of the unit drivecircuits USU(0) to USU(6) turns the tenth switch USW1 and the eleventhswitch USW2 inside the corresponding unit selection circuits UUC(0) toUUC(6) into the off-state using the selection signals S10 to S16 and S20to S26. Meanwhile, the selection information SEI is sequentially shiftedin the unit drive circuits USD(0) to USD(6). For example, when theselection information SEI is set to the unit drive circuit USD(0), theunit drive circuit USD(0) turns the twelfth switch USW3 into theon-state using the selection signal S30. Accordingly, the driveelectrode TL(0) is connected to the voltage wiring VCOM via the twelfthswitch USW3. In the fifth embodiment, the control circuit D-CNT (FIG. 8)supplies an electric field drive signal with periodically changingvoltage to the voltage wiring VCOM in the case of electric field touchdetection. Accordingly, the drive electrode TL(0) generates an electricfield according to the electric field drive signal at the time ofelectric field touch detection.

Incidentally, the thirteenth switch USW4 and the fourteenth switch USW5in the unit selection circuit UDC(0) are turned into the off-state atthis time. In addition, the twelfth switch USW3, the thirteenth switchUSW4, and the fourteenth switch USW5 in each of the remaining unitselection circuits USD(1) to USD(6) are also turned into the off-state.

As the selection information SEI is shifted from the unit drive circuitUSD(0) toward USD(6), the electric fields are sequentially generatedfrom the drive electrode TL(2) toward TL(6).

Although the description has been given regarding the example where theelectric field drive signal with the periodically changing voltage issupplied to the voltage wiring VCOM at the time of electric field touchdetection, the invention is not limited thereto. For example, thethirteenth switch USW4 and the fourteenth switch USW5 may becomplementarily turned into the on/off state using the selection signalS40 instead of turning the twelfth switch USW3 into the on-state usingthe selection signal S30. As the thirteenth switch USW4 and thefourteenth switch USW5 are complementarily turned into the on/off state,the drive electrode TL(0) is alternately connected to the voltagewirings TPH and TPL. As a result, the voltage that changes with time issupplied to the drive electrode TL(0), and it is possible to generatethe electric field that changes with time.

The magnetic field detection coil can be formed using the detectionelectrodes RL(0) to RL(p) or the scan lines GL(0) to GL(p) at the timeof magnetic field touch detection, similarly to the description in thefourth embodiment. In addition, for example, the scan line can be usedas the detection electrode to detect the change of the electric chargeamount at the time of electric field touch detection.

Modified Example

FIG. 33 is a circuit diagram illustrating configurations of selectiondrive circuits SSU and SSD according to a modified example of the fifthembodiment. FIG. 33 is drawn in accordance with actual arrangementalthough being schematic. FIG. 33 is similar to FIG. 32, and so adifferent point will be mainly described here.

In the configuration illustrated in FIG. 32, each of the voltage wiringsTPL and TPH is arranged to surround the display panel 2. In regard tothis, the voltage wiring TPL is arranged in an area between the side 2-Lof the display panel 2 and the side 900-L of the module 900 (FIG. 9),and the voltage wiring TPH is arranged in an area between the side 2-Rof the display panel 2 and the side 900-R of the module 900 in themodified example illustrated in FIG. 33. In other words, the voltagewiring TPH is not arranged in the area between the side 2-L of thedisplay panel 2 and the side 900-L of the module 900 (FIG. 9), and thevoltage wiring TPL is not arranged in the area between the side 2-R ofthe display panel 2 and the side 900-R of the module 900 (FIG. 9). Thatis, only one of the voltage wirings TPH and TPL is arranged in the rightand left frames.

In the modified example, the voltage wirings TPL and TPH are arranged inan area between the side 2-U of the display panel 2 and the side 900-Uof the module 900, and the voltage wirings TPL and TPH are also arrangedin an area between the side 2-D of the display panel 2 and the side900-D of the module 900. In addition, the voltage wiring TPL arranged inthe area between the side 2-U and the side 900-U is connected to thevoltage wiring TPL arranged in the area between the side 2-D and theside 900-D via the voltage wiring TPL arranged in the area between theside 2-L and the side 900-L. Further, the voltage wiring TPH arranged inthe area between the side 2-U and the side 900-U is connected to thevoltage wiring TPR arranged in the area between the side 2-D and theside 900-D via the voltage wiring TPR arranged in the area between theside 2-R and the side 900-R.

Accordingly, it is possible to supply the ground voltage Vss and thepredetermined voltage to the selection drive circuit SSU arranged alongthe side 2-U of the display panel 2 and the selection drive circuit SSDarranged along the side 2-D of the display panel 2 while suppressing theincrease of the frame.

Sixth Embodiment

FIG. 34 is a schematic plan view illustrating a configuration of thedisplay device 1 according to a sixth embodiment. FIG. 34 is also drawnin accordance with actual arrangement although being schematic. In thedisplay device 1 according to the sixth embodiment, the description willbe given also regarding an example where a magnetic field is generatedin the magnetic field generation period TGT using a drive electrodearranged in parallel to the signal lines SL(0) to SL(p) similarly to thefifth embodiment.

FIG. 34 illustrates a part relating to the display panel 2 similarly toFIG. 31. FIG. 34 is similar to FIG. 31, and so a different point will bemainly described here. In FIG. 31, the predetermined voltage serving asthe drive signal and the ground voltage Vss are supplied to the pair ofdrive electrodes by the selection drive circuit SSU including the drivecircuit SU-R and the selection circuit SU-C in the magnetic fieldgeneration period TGT to generate the magnetic field. Thus, the voltagewirings TPL and TPH are arranged along the side 2-U of the display panel2, and the ground voltage Vss and the predetermined voltage are suppliedto the selection circuit SU-C.

In the sixth embodiment, the selection drive circuit SSU-S is alsoarranged along the side 2-U of the display panel 2. The selection drivecircuit SSU-S according to the sixth embodiment is provided with thedrive circuit SU-R and a selective connection circuit SU-S. Theselective connection circuit SU-S is different from the selectioncircuit SU-C that has been described in the fifth embodiment, and formsa magnetic field generation coil by connecting signal wirings arrangedto be parallel to the signal lines SL(0) to SL(p) to each other in themagnetic field generation period TGT. Here, drive electrodes and voltagewirings arranged along the sides 2-L and 2-R of the display panel 2correspond to the signal wirings arranged to be parallel to the signallines SL(0) to SL(p).

In the case of focusing on the voltage wiring TPH arranged in the areabetween the side 2-L of the display panel 2 and the side 900-L of themodule 900 and the voltage wiring TPL arranged in the area between theside 2-R of the display panel 2 and the side 900-R of the module 900,both voltage wirings are used to supply the predetermined voltage andthe ground voltage Vss to the selection circuit SU-C in the fifthembodiment. In regard to this, the voltage wirings TPL and TPH, whichare arranged along the side 2-L and the side 2-R of the display panel 2,are also used as windings of a magnetic field generation coil in thesixth embodiment although not particularly limited thereto.

<Configuration of Selective Connection Circuit>

FIG. 35 is a circuit diagram illustrating a configuration of theselection drive circuit SSU-S according to the sixth embodiment. FIG. 35is drawn in accordance with actual arrangement although being schematic.In FIG. 35, the selection drive circuit SSD and the drive electrodesTL(0) to TL(6) are the same as those in FIG. 32, and so the descriptionthereof will be omitted.

Similarly to FIG. 32, the drive circuit SU-R includes the plurality ofunit drive circuits USU(0) to USU(6). Each of the unit drive circuitsUSU(0) to USU(6) has the shift stage. The respective shift stages of theunit drive circuits USU(0) to USU(6) are connected in series, and theselection information SEI set to the unit drive circuit USU(0) isshifted toward the unit drive circuit USU(6) in synchronization with aclock signal (not illustrated). Each of the unit drive circuits USU(0)to USU(6) outputs selection signals S50 to S56 indicating selection asthe selection information SEI indicating selection is set thereto. Forexample, the unit drive circuit USU(3) outputs the selection signal S53indicating the selection when the selection information SEI indicatingthe selection is shifted from the unit drive circuit USU(2) at theprevious stage and is supplied thereto.

The selective connection circuit SU-S includes fifteenth switchesUSW6(0) to USW6(6) which correspond to the unit drive circuits USU(0) toUSU(6), respectively. Each of the fifteenth switches USW6(0) to USW(6)is connected among each of the drive electrodes TL(0) to TL(6), avoltage wiring TL(TPH) arranged along the side 2-L of the display panel2, and a voltage wiring TL(TPL) arranged along the side 2-R of thedisplay panel 2 so that one drive electrode is sandwiched therebetween.In FIG. 35, the voltage wiring TL(TPH) represents an area arranged alongthe side 2-L of the display panel 2 in the voltage wiring TPH, and thevoltage wiring TL(TPL) represents an area arranged along the side 2-R ofthe display panel 2 in the voltage wiring TPL. The voltage wiringsTL(TPH) and TL(TPL) are arranged along the side 2-L and the side 2-R ofthe display panel 2, and thus are parallel to the drive electrodes TL(0)to TL(6).

The fifteenth switch USW6(0) is connected between the voltage wiringTL(TPH) and one end portion of the drive electrode TL(1) and issubjected to switch control by the selection signal S50 sent from theunit drive circuit USU(0); the fifteenth switch USW6(1) is connectedbetween the one end portions of the respective drive electrode TL(0) anddrive electrode TL(2), and is subjected to switch control by theselection signal S51 sent from the unit drive circuit USU(1); and thefifteenth switch USW6(2) is connected between one end portions of therespective drive electrode TL(1) and drive electrode TL(3), and issubjected to switch control by the selection signal S52 sent from theunit drive circuit USU(2). In addition, the fifteenth switch USW6(3) isconnected between one end portions of the respective drive electrodeTL(2) and drive electrode TL(4), and is subjected to switch control bythe selection signal S53 sent from the unit drive circuit USU(3); andthe fifteenth switch USW6(4) is connected between one end portions ofthe respective drive electrode TL(3) and drive electrode TL(5), and issubjected to switch control by the selection signal S54 sent from theunit drive circuit USU(4).

Similarly, the fifteenth switch USW6(5) is connected between one endportions of the respective drive electrode TL(4) and drive electrodeTL(6), and is subjected to switch control by the selection signal S55sent from the unit drive circuit USU(5); and the fifteenth switchUSW6(6) is connected between one end portion of the drive electrodeTL(5) and the voltage wiring TL(TPL), and is subjected to switch controlby the selection signal S56 sent from the unit drive circuit USU(6).

In the sixth embodiment, when the unit drive circuit USU(0) outputs theselection signal S50 indicating the selection in the magnetic fieldgeneration period TGT, the unit drive circuit USD(1) outputs theselection signal S41 so that the thirteenth switch USW4 inside the unitselection circuit UDC(1) is turned into the on-state, and that thefourteenth switch USW5 is turned into the off-state. Since the fifteenthswitch USW6(0) is turned into the on-state by the selection signal S50,the voltage wiring TL(TPH) and the drive electrode TL(1), which arearranged in parallel to each other, are connected in series. As aresult, a magnetic field generation coil using the voltage wiringTL(TPH) and the drive electrode TL(1) as a winding is formed. When acurrent flows in the voltage wiring TL(TPH) and the drive electrodeTL(1) connected in series, a magnetic field is generated around each ofthe voltage wiring TL(TPH) and the drive electrode TL(1). The generatedmagnetic fields are superimposed on each other in an area of the driveelectrode TL(0) sandwiched between the voltage wiring TL(TPH) and thedrive electrode TL(1), thereby generating a strong magnetic field.

Next, when the selection information SEI indicating the selection isshifted to the unit drive circuit USU(1), the fifteenth switch USW6(1)is turned into the on-state by the selection signal S51. At this time,the unit drive circuit USD(0) outputs the selection signal S40 so thatthe fourteenth switch USW5 inside the unit selection circuit UDC(0) isturned into the on-state and the thirteenth switch USW4 is turned intothe off-state. In addition, the unit selection circuit UDC(2) outputsthe selection signal S42 so that the thirteenth switch USW4 inside theunit selection circuit UDC(2) is turned into the on-state and thefourteenth switch USW5 is turned into the off-state. Since the fifteenthswitch USW6(1) is turned into the on-state, the drive electrodes TL(0)and TL(2), which are arranged in parallel to each other, are connectedin series, and a magnetic field generation coil using these driveelectrodes as a winding is formed. In addition, magnetic fields aregenerated as a current flows in the drive electrodes TL(0) and TL(2)connected in series, and the generated magnetic fields are superimposedon each other in an area of the drive electrode TL(1).

In the same manner after this, the fifteenth switches are sequentiallyturned into the on-state, two drive electrodes are connected in series,and a current flows in the drive electrodes connected in series, therebygenerating a strong magnetic field. In addition, a magnetic fieldgeneration coil using the drive electrode TL(5) and the voltage wiringTL(TPL) as a winding is formed when the fifteenth switch USW6(6) isturned into the on-state by the selection signal S56 sent from the unitdrive circuit USU(6). In this case, a strong magnetic field is generatedin an area of the drive electrode TL(6).

Although the description has been given in FIG. 35 regarding the casewhere one drive electrode is sandwiched therebetween, the invention isnot limited thereto. For example, two or more drive electrodes may besandwiched, or no drive electrode may be sandwiched therebetween. Forexample, when the two drive electrodes are sandwiched therebetween, thefifteenth switch USW6(0) is connected between the voltage wiring TL(TPH)and the drive electrode TL(2), and the fifteenth switch USW6(1) isconnected between the drive electrode TL(0) and the drive electrodeTL(3). On the other hand, when no drive electrode is sandwichedtherebetween, the fifteenth switch USW6(0) is connected between thevoltage wiring TL(TPH) and the drive electrode TL(0), and the fifteenthswitch USW6(1) is connected between the drive electrode TL(0) and thedrive electrode TL(1).

The magnetic field detection coil and the electric field detectionelectrode may be provided in the same manner as the fifth embodiment. Inaddition, the electric field touch detection can be realized in the samemanner as the fifth embodiment.

In the sixth embodiment, the voltage wirings TL(TPH) and TL(TPL), whichare arranged outside the display panel 2 along the sides of the displaypanel 2, are also used as the winding of the magnetic field generationcoil. Thus, it is possible to detect touch by a pen even in each partproximate to the side 2-L and the side 2-R of the display panel 2. Ofcourse, only one of the voltage wirings may be used as the winding ofthe magnetic field generation coil, or the voltage wirings TL(TPH) andTL(TPL) may not necessarily used as the winding of the magnetic fieldgeneration coil. In addition, the description has been given in FIG. 35by exemplifying the magnetic field generation coil having a one-turnwinding, but the magnetic field generation coil may have a winding withone and half turns or more.

In the present specification, the drive wiring, for example, the driveelectrode, the signal line or the scan line, which generates themagnetic field in the magnetic field generation period TGT, includes apair of end portions. The other end portion (or one end portion) out ofthe pair of end portions is present in the extending direction of thedrive wiring with respect to one end portion (or the other end portion).The drive signal is supplied to the one end portion (or the other endportion), and the ground voltage Vss serving as a reference signal issupplied to the other end portion (or the one end portion) at the timeof generating the magnetic field. When the one end portion and the otherend portion are regarded as a first area and a second area of the drivewiring, the drive signal can be regareded as being supplied to the firstarea (or the second area) of the drive wiring, and the reference signalcan be regarded as being supplied to the second area (or the first area)in the magnetic field generation period TGT.

When FIG. 8 of the first embodiment is exemplified, the drive wiringwhich generates the magnetic field correspond to the drive electrodesTL(0) to TL(p) extending in the row direction in the magnetic fieldgeneration period TGT, and the first area (second area) is present inthe direction extending in the row direction with respect to the secondarea (first area). In addition, when the plurality of drive electrodesTL(0) to TL(p) are regarded as a plurality of drive wirings, one driveelectrode out of a pair of drive electrodes, which is selected by theselection signal sent from the unit drive circuit in the magnetic fieldgeneration period TGT, can be regarded as a first drive wiring, and theother drive electrode can be regarded as a second drive wiring. In thiscase, respective one end portions (for example, the first areas) of thefirst drive wiring and the second drive wiring are arranged on the sameside (for example, the side 2-L) of the display panel 2 side, and therespective other end portions (the second areas) are arranged on thesame side (the side 2-R) of the display panel 2 side. Thus, therespective first areas (one end portions) of the first drive wiring andthe second drive wiring are proximate to each other, and the respectivesecond areas (the other end portions) of the first drive wiring and thesecond drive wiring are proximate to each other.

In addition, when one or more drive wirings (the drive electrode in FIG.8) are sandwiched between the selected pair of drive wirings in themagnetic field generation period TGT, the sandwiched drive wiring(s) canbe regarded as a third drive wiring. Further, when the drive electrodesTL(0) to TL(p) are regarded as the drive wirings by exemplifying FIG. 8,the signal lines SL(0) to SL(p), which extend in the column direction tocross the drive electrodes TL(0) to TL(p), can be regarded as detectionwirings. Of course, the detection wirings are not limited to the signallines SL(0) to SL(p) but may be the scan lines GL(0) to GL(p) or thedetection electrodes RL(0) to RL(p).

It is understood that those skilled in the art can derive various typesof modified examples and corrections in the category of the idea of thepresent invention, and these modified example and corrections areencompassed within the scope of the present invention.

Any one obtained when those skilled in the art appropriately modify theabove embodiments by addition, deletion, or design change of components,or by addition, omission, or condition change of steps is alsoencompassed within the scope of the invention as long as it includes agist of the invention.

For example, the description has been given in the embodiments regardingthe case where the common electrodes TL(0) to TL(p) and the signal linesSL(0) to SL(p) extend in the column direction and are arranged in therow direction, but the row direction and the column direction arechanged depending on a point of view. A case where the point of view ischanged so that the common electrodes TL(0) to TL(p) and the signallines SL(0) to SL(p) extend in the row direction and are arranged in thecolumn direction is also included in the scope of the present invention.In addition, the expression “parallel” used in the present specificationmeans to extend without intersecting each other from one end to theother end. Thus, when lines do not intersect each other from one end tothe other end even though a part or the entire part of one line isprovided in the state of being inclined to the other line, this state isalso considered as “parallel” in the present specification. In addition,the description has been given in FIG. 18 regarding the example wherethe drive electrode except for the drive electrode that generates theelectric field is connected to the voltage wiring VCOM at the time ofelectric field touch detection. But, the invention is not limitedthereto, and the drive electrode except for the drive electrode thatgenerates the electric field may be set to the floating state.

What is claimed is:
 1. A display device comprising: a pixel arrayincluding a plurality of pixels arranged in a matrix form; a pluralityof drive electrodes each of which extends in a first direction and isarranged in a second direction intersecting the first direction in adetection area for detecting an external proximity object; a pluralityof detection electrodes each of which extends in the second directionand is arranged in the first direction in the detection area, a firstdrive wiring extending in the second direction so as to face to one endportions of the plurality of drive electrodes and providing an ACvoltage to the one end portions of the drive electrodes; a second drivewiring extending in the second direction so as to face to the other endportions of the plurality of drive electrodes and providing an ACvoltage to the other end portions of the drive electrodes; a firstreference voltage wiring extending in the second direction so as to faceto the one end portions of the plurality of drive electrodes andproviding a first reference voltage to the drive electrodes, wherein thefirst reference voltage wiring is located farther from the one endportions of the plurality of drive electrodes than the first drivewiring; a second reference voltage wiring extending in the seconddirection so as to face to the other end portions of the plurality ofdrive electrodes and providing a second reference voltage to the driveelectrodes, wherein the second reference voltage wiring is locatedfarther from the other end portions of the plurality of drive electrodesthan the second drive wiring; a plurality of first switch circuitcoupling the one end portions of the driving electrodes to one of thefirst drive wiring and the first reference voltage wiring; and aplurality of second switch circuit coupling the other end portions ofthe driving electrodes to one of the second drive wiring and the secondreference voltage wiring.
 2. The display device according to claim 1,wherein the plurality of drive electrodes includes a drive electrode ofwhich the other end portion is coupled to the first reference voltagewiring while a one end portion of the drive electrode is coupled to thefirst drive wiring by a first switch circuit, and of which the one endportion is coupled to the second reference voltage wiring while theother end portion of the drive electrode is coupled to the second drivewiring by a second switch circuit.
 3. The display device according toclaim 2, wherein a drive electrode generates a magnetic field accordingto the AC voltage at time of detecting the external proximity object,and the detection electrodes detects a magnetic field generated by theexternal proximity object in response to the magnetic field generated bythe drive electrode.
 4. The display device according to claim 3, whereinthe plurality of drive electrodes are arranged in parallel to eachother, the plurality of drive electrodes including a second driveelectrode is arranged to be proximate to a first drive electrode, and aone end portion of the first drive electrode is coupled to the firstdrive wiring and a one end portion of the second drive electrode iscoupled to the second reference voltage wiring at time of detecting theexternal proximity object, and the other end portion of the first driveelectrode is coupled to the first reference voltage and the other endportion of the second drive electrode is coupled to the second drivewiring at the time of detecting the external proximity object, wherebythe magnetic field generated by the first drive electrode and themagnetic field generated by the second electrode are superimposed oneach other in an area between the first drive electrode and the seconddrive electrode at the time of detecting the external proximity object.5. The display device according to claim 4, wherein a direction of acurrent flowing in the second drive electrode is an opposite directionto a direction of current flowing in the first drive electrode at thetime of detecting the external proximity object.
 6. The display deviceaccording to claim 5, wherein the plurality of drive electrodes includesa third drive electrode which is arranged between the first driveelectrode and the second drive electrode.
 7. The display deviceaccording to claim 6, wherein a plurality of stages of an operation ofdetecting the external proximity object is executed during a displayperiod for one frame in the pixel array, a number of the third drivewirings is set to a predetermined value at a predetermined stage, andthe number of third drive wirings is set to be smaller than thepredetermined value at a stage after the predetermined stage.
 8. Thedisplay device according to claim 6, wherein the first drive electrodeincludes a plurality of drive electrodes arranged to be adjacent to eachother, and the second drive electrode includes a plurality of driveelectrodes arranged to be adjacent to each other.
 9. The display deviceaccording to claim 3, further comprising: A plurality of signal lines,which supply signals to the plurality of pixels at time of display, anda plurality of drive lines which intersect the plurality of signal linesare arranged in the pixel array, the plurality of drive electrodesinclude the plurality of drive lines, and the plurality of detectionelectrodes include the plurality of signal lines.
 10. The display deviceaccording to claim 3, wherein the pixel array includes a first substrateon which a plurality of signal wirings are formed and a layer which isinterposed between the first substrate and a second substrate arrangedto oppose the first substrate and is displaced depending on signals thatneed to be displayed, the plurality of drive electrodes include theplurality of signal wirings formed on the first substrate, and theplurality of detection electrodes include a signal wiring formed on thesecond substrate.
 11. The display device according to claim 3, whereinthe pixel array includes a plurality of signal lines, which are arrangedalong each column of the pixel array and supply signals to the pluralityof pixels, and a plurality of scan lines which are arranged along eachrow of the pixel array and supply a scan signal to select the pixelarranged in the row, and the plurality of drive electrodes include theplurality of signal lines or the plurality of scan lines.
 12. Thedisplay device according to claim 11, further comprising: a plurality ofmatrix electrodes which are arranged in a dot matrix form in the pixelarray; and a plurality of detection signal lines which are connected tothe plurality of matrix electrodes, wherein the plurality of detectionsignal lines are arranged in parallel to the plurality of signal linesand detect the external proximity object based on a change of a chargeamount in the matrix electrodes.
 13. The display device according toclaim 12, further comprising: a first substrate on which the pluralityof signal lines, the plurality of scan lines, the plurality of detectionsignal lines, and the plurality of matrix electrodes are formed; and asecond substrate which is arranged to oppose the first substrate with alayer, displaced depending on the signals that need to be displayed,interposed therebetween, wherein the plurality of detection electrodesinclude a plurality of signal wirings formed on the second substrate.14. The display device according to claim 3, further comprising: acontrol circuit coupled to the first drive wiring, the second drivewiring, the first reference voltage wiring and the second referencevoltage wiring, providing the AC voltage to the first drive wiring andthe second drive wiring and providing the first reference voltage andthe second reference voltage to the first drive wiring and the seconddrive wiring at time of detecting the external proximity object.
 15. Thedisplay device according to claim 14, wherein the plurality of driveelectrodes includes a first drive electrode having the other end portioncoupled to the first reference voltage wiring while a one end portion ofthe first drive electrode is coupled to the first drive wiring by afirst switch circuit, and wherein the plurality of drive electrodesincludes a second drive electrode having a one end portion coupled tothe second reference voltage wiring while the other end portion of thesecond drive electrode is coupled to the second drive wiring by a secondswitch circuit.
 16. The display device according to claim 15, whereinthe plurality of drive electrodes includes a third drive electrode whichis arranged between the first drive electrode and the second driveelectrode, and the third drive electrode is isolated from the firstdrive wiring and the second drive wiring or from the first referencevoltage wiring and the second reference voltage wiring.
 17. The displaydevice according to claim 15, wherein the third drive electrode isisolated from the first drive wiring, the second drive wiring, the firstreference voltage wiring and the second reference voltage wiring.
 18. Adisplay device comprising: a pixel array including a plurality of pixelsarranged in a matrix form; a plurality of drive electrodes each of whichextends in a first direction and is arranged on a second directionintersecting the first direction in a detection area for detecting anexternal proximity object; a plurality of detection electrodes each ofwhich extends in the second direction and is arranged in the firstdirection in the detection area; a first drive wiring extending in thesecond direction so as to face to one end portions of the plurality ofdrive electrodes; a second drive wiring extending in the seconddirection so as to face to the other end portions of the plurality ofdrive electrodes; a first reference wiring extending in the seconddirection so as to face to the other end portions of the plurality ofdrive electrodes; a second reference wiring extending in the seconddirection so as to face to the one end portions of the plurality ofdrive electrodes; a plurality of first switch circuit coupling among theone end portions of the driving electrodes, the first drive wiring andthe second reference wiring and a plurality of second switch circuitcoupling among the other end portions of the driving electrodes, thesecond drive wiring and the first reference wiring, wherein theplurality of drive electrode includes a first drive electrode and asecond drive electrode in which currents follow at time of detecting theexternal proximity object.
 19. The display device according to claim 18,wherein a direction of a current flowing in the second drive electrodeis an opposite direction to a direction of current flowing in the firstdrive electrode at the time of detecting the external proximity object.